The Debian GNU/Linux FAQ ------------------------ Authors are listed at Debian FAQ Authors version 4.0.4+nmu1, 3 January 2010 ------------------------------------------------------------------------------- Abstract -------- This document answers questions frequently asked about Debian GNU/Linux. Copyright Notice ---------------- Copyright (C) 1996-2005 by Software in the Public Interest, portions copyright (C) 2004, 2005, 2006 Kamaraju Kusumanchi Permission is granted to make and distribute verbatim copies of this document provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this document under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this document into another language, under the above conditions for modified versions, except that this permission notice may be included in translations approved by the Free Software Foundation instead of in the original English. ------------------------------------------------------------------------------- Contents -------- 1. Definitions and overview 1.1. What is this FAQ? 1.2. What is Debian GNU/Linux? 1.3. OK, now I know what Debian is... what is Linux?! 1.4. Does Debian just do GNU/Linux? 1.5. What is the difference between Debian GNU/Linux and other Linux distributions? Why should I choose Debian over some other distribution? 1.6. How does the Debian project fit in or compare with the Free Software Foundation's GNU project? 1.7. How does one pronounce Debian and what does this word mean? 2. Getting and installing Debian GNU/Linux 2.1. What is the latest version of Debian? 2.2. Are there package upgrades in `stable'? 2.3. Where/how can I get the Debian installation disks? 2.4. How do I install the Debian from CD-ROMs? 2.5. Why does the official stable released CD-ROM contain symlinks for `frozen' and `unstable'? I thought this CD contains just `stable'! 2.6. Can I get and install Debian directly from a remote Internet site? 2.7. Are there any alternative strategies for booting the system installer? 3. Choosing a Debian distribution 3.1. Which Debian distribution (stable/testing/unstable) is better for me? 3.1.1. You asked me to install stable, but in stable so and so hardware is not detected/working. What should I do? 3.1.2. Will there be different different versions of packages in different distributions? 3.1.3. The stable distributions really contains outdated packages. Just look at Kde, Gnome, Xorg or even the kernel. They are very old. Why is it so? 3.1.4. If I were to decide to change to another distribution, Can I do that? 3.1.5. Could you tell me whether to install testing or unstable? 3.1.6. You are talking about testing being broken. What do you mean by that? 3.1.7. Why is it that testing could be broken for months? Wont the fixes introduced in unstable flow directly down into testing? 3.1.8. From an administrator's point of view, Which distribution requires more attention? 3.1.9. What happens when a new release is made? 3.1.10. I have a working Desktop/cluster with Debian installed. How do I know which distribution I am running? 3.1.11. I am currently tracking stable. Can I change to testing or unstable? If so, How? 3.1.12. I am currently tracking testing (lenny). What will happen when a release is made? Will I still be tracking testing or will my machine be running the new stable distribution? 3.1.13. I am still confused. What did you say I should install? 3.2. But what about Knoppix, Linex, Ubuntu, and others? 3.2.1. I know that Knoppix/Linex/Ubuntu/... is Debian-based. So after installing it on the hard disk, can I use 'apt' package tools on it? 3.2.2. I installed Knoppix/Linex/Ubuntu/... on my hard disk. Now I have a problem. What should I do? 3.2.3. I'm using Knoppix/Linex/Ubuntu/... and now I want to use Debian. How do I migrate? 4. Compatibility issues 4.1. On what hardware architectures/systems does Debian GNU/Linux run? 4.2. How compatible is Debian with other distributions of Linux? 4.3. How source code compatible is Debian with other Unix systems? 4.4. Can I use Debian packages (".deb" files) on my Red Hat/Slackware/... Linux system? Can I use Red Hat packages (".rpm" files) on my Debian GNU/Linux system? 4.5. How should I install a non-Debian program? 4.6. Why can't I compile programs that require libtermcap? 4.7. Why can't I install AccelX? 4.8. Why do my old XFree 2.1 Motif applications crash? 5. Software available in the Debian system 5.1. What types of applications and development software are available for Debian GNU/Linux? 5.2. Who wrote all that software? 5.3. How can I get a current list of programs that have been packaged for Debian? 5.4. How can I install a developer's environment to build packages? 5.5. What is missing from Debian GNU/Linux? 5.6. Why do I get "ld: cannot find -lfoo" messages when compiling programs? Why aren't there any libfoo.so files in Debian library packages? 5.7. (How) Does Debian support Java? 5.8. How can I check that I am using a Debian system, and what version is it? 5.9. How does Debian support non-English languages? 5.10. Where is pine? 5.11. Where is qmail/ezmlm/djbdns? 5.12. Where is a player for Flash (SWF)? 5.13. Where is Google Earth? 5.14. Where is VoIP software? 5.15. I have a wireless network card which doesn't work with Linux. What should I do? 6. The Debian FTP archives 6.1. How many Debian distributions are there? 6.2. What are all those names like etch, lenny, etc.? 6.2.1. Which other codenames have been used in the past? 6.2.2. Where do these codenames come from? 6.3. What about "sid"? 6.4. What does the stable directory contain? 6.5. What does the testing distribution contain? 6.5.1. What about "testing"? How is it `frozen'? 6.6. What does the unstable distribution contain? 6.7. What are all those directories at the Debian FTP archives? 6.8. What are all those directories inside `dists/stable/main'? 6.9. Where is the source code? 6.10. What's in the `pool' directory? 6.11. What is "incoming"? 6.12. How do I set up my own apt-able repository? 7. Basics of the Debian package management system 7.1. What is a Debian package? 7.2. What is the format of a Debian binary package? 7.3. Why are Debian package file names so long? 7.4. What is a Debian control file? 7.5. What is a Debian conffile? 7.6. What is a Debian preinst, postinst, prerm, and postrm script? 7.7. What is an _Essential_, _Required_, _Important_, _Standard_, _Optional_, or _Extra_ package? 7.8. What is a Virtual Package? 7.9. What is meant by saying that a package _Depends_, _Recommends_, _Suggests_, _Conflicts_, _Replaces_ or _Provides_ another package? 7.10. What is meant by Pre-Depends? 7.11. What is meant by _unknown_, _install_, _remove_, _purge_ and _hold_ in the package status? 7.12. How do I put a package on hold? 7.13. How do I install a source package? 7.14. How do I build binary packages from a source package? 7.15. How do I create Debian packages myself? 8. The Debian package management tools 8.1. What programs does Debian provide for managing its packages? 8.1.1. dpkg 8.1.2. APT 8.1.3. aptitude 8.1.4. synaptic 8.1.5. tasksel 8.1.6. Other package management tools 8.2. Debian claims to be able to update a running program; how is this accomplished? 8.3. How can I tell what packages are already installed on a Debian system? 8.4. How to display the files of a package installed? 8.5. How can I find out what package produced a particular file? 8.6. Why doesn't get `foo-data' removed when I uninstall `foo'? How do I make sure old unused library-packages get purged? 9. Keeping your Debian system up-to-date 9.1. How can I keep my Debian system current? 9.1.1. aptitude 9.1.2. apt-get, dselect and apt-cdrom 9.1.3. aptitude 9.1.4. mirror 9.1.5. dpkg-mountable 9.2. Must I go into single user mode in order to upgrade a package? 9.3. Do I have to keep all those .deb archive files on my disk? 9.4. How can I keep a log of the packages I added to the system? I'd like to know when which package upgrades and removals have occured! 9.5. Can I automatically update the system? 9.6. I have several machines how can I download the updates only one time? 10. Debian and the kernel 10.1. Can I install and compile a kernel without some Debian-specific tweaking? 10.2. What tools does Debian provide to build custom kernels? 10.3. How can I make a custom boot floppy? 10.4. What special provisions does Debian provide to deal with modules? 10.5. Can I safely de-install an old kernel package, and if so, how? 11. Customizing your installation of Debian GNU/Linux 11.1. How can I ensure that all programs use the same paper size? 11.2. How can I provide access to hardware peripherals, without compromising security? 11.3. How do I load a console font on startup the Debian way? 11.4. How can I configure an X11 program's application defaults? 11.5. Every distribution seems to have a different boot-up method. Tell me about Debian's. 11.6. It looks as if Debian does not use `rc.local' to customize the boot process; what facilities are provided? 11.7. How does the package management system deal with packages that contain configuration files for other packages? 11.8. How do I override a file installed by a package, so that a different version can be used instead? 11.9. How can I have my locally-built package included in the list of available packages that the package management system knows about? 11.10. Some users like mawk, others like gawk; some like vim, others like elvis; some like trn, others like tin; how does Debian support diversity? 12. Getting support for Debian GNU/Linux 12.1. What other documentation exists on and for a Debian system? 12.2. Are there any on-line resources for discussing Debian? 12.2.1. Mailing lists 12.2.2. Web forums 12.2.3. Wiki 12.2.4. Maintainers 12.2.5. Usenet newsgroups 12.3. Is there a quick way to search for information on Debian GNU/Linux? 12.4. Are there logs of known bugs? 12.5. How do I report a bug in Debian? 13. Contributing to the Debian Project 13.1. How can I become a Debian software developer? 13.2. How can I contribute resources to the Debian project? 13.3. How can I contribute financially to the Debian project? 13.3.1. Software in the Public Interest 13.3.2. Free Software Foundation 14. Redistributing Debian GNU/Linux in a commercial product 14.1. Can I make and sell Debian CDs? 14.2. Can Debian be packaged with non-free software? 14.3. I am making a special Linux distribution for a "vertical market". Can I use Debian GNU/Linux for the guts of a Linux system and add my own applications on top of it? 14.4. Can I put my commercial program in a Debian "package" so that it installs effortlessly on any Debian system? 15. Changes expected in the next major release of Debian 15.1. Extended support for non-English users 15.2. Faster booting: Dependency based boot sequence 15.3. Improvements in the Debian Installer 15.4. More architectures 15.5. More kernels 16. General information about the FAQ 16.1. Authors 16.2. Feedback 16.3. Availability 16.4. Document format ------------------------------------------------------------------------------- 1. Definitions and overview --------------------------- 1.1. What is this FAQ? ---------------------- This document gives frequently asked questions (with their answers!) about the Debian distribution (Debian GNU/Linux and others) and about the Debian project. If applicable, pointers to other documentation will be given: we won't quote large parts of external documentation in this document. You'll find out that some answers assume some knowledge of Unix-like operating systems. We'll try to assume as little prior knowledge as possible: answers to general beginners questions will be kept simple. If you can't find what you're looking for in this FAQ, be sure to check out Section 12.1, `What other documentation exists on and for a Debian system?'. If even that doesn't help, refer to Section 16.2, `Feedback'. 1.2. What is Debian GNU/Linux? ------------------------------ Debian GNU/Linux is a particular _distribution_ of the Linux operating system, and numerous packages that run on it. Debian GNU/Linux is: * _full featured_: Debian includes more than 18200 software packages at present. Users can select which packages to install; Debian provides a tool for this purpose. You can find a list and descriptions of the packages currently available in Debian at any of the Debian mirror sites (http://www.debian.org/distrib/ftplist). * _free to use and redistribute_: There is no consortium membership or payment required to participate in its distribution and development. All packages that are formally part of Debian GNU/Linux are free to redistribute, usually under terms specified by the GNU General Public License. The Debian FTP archives also carry approximately 560 software packages (in the `non-free' and `contrib' sections), which are distributable under specific terms included with each package. * _dynamic_: With about 1060 volunteers constantly contributing new and improved code, Debian is evolving rapidly. The FTP archives are updated twice every day. Most Linux users run a specific _distribution_ of Linux, like Debian GNU/Linux. However, in principle, users could obtain the Linux kernel via the Internet or from elsewhere, and compile it themselves. They could then obtain source code for many applications in the same way, compile the programs, then install them into their systems. For complicated programs, this process can be not only time-consuming but error-prone. To avoid it, users often choose to obtain the operating system and the application packages from one of the Linux distributors. What distinguishes the various Linux distributors are the software, protocols, and practices they use for packaging, installing, and tracking applications packages on users' systems, combined with installation and maintenance tools, documentation, and other services. Debian GNU/Linux is the result of a volunteer effort to create a free, high-quality Unix-compatible operating system, complete with a suite of applications. The idea of a free Unix-like system originates from the GNU project, and many of the applications that make Debian GNU/Linux so useful were developed by the GNU project. For Debian, free has the GNUish meaning (see the Debian Free Software Guidelines (http://www.debian.org/social_contract#guidelines)). When we speak of free software, we are referring to freedom, not price. Free software means that you have the freedom to distribute copies of free software, that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs; and that you know you can do these things. The Debian Project was created by Ian Murdock in 1993, initially under the sponsorship of the Free Software Foundation's GNU project. Today, Debian's developers think of it as a direct descendent of the GNU project. Although Debian GNU/Linux itself is free software, it is a base upon which value-added Linux distributions can be built. By providing a reliable, full-featured base system, Debian provides Linux users with increased compatibility, and allows Linux distribution creators to eliminate duplication of effort and focus on the things that make their distribution special. See Section 14.3, `I am making a special Linux distribution for a "vertical market". Can I use Debian GNU/Linux for the guts of a Linux system and add my own applications on top of it?' for more information. 1.3. OK, now I know what Debian is... what is Linux?! ----------------------------------------------------- In short, Linux is the kernel of a Unix-like operating system. It was originally designed for 386 (and better) PCs; today Linux also runs on a dozen of other systems. Linux is written by Linus Torvalds and many computer scientists around the world. Besides its kernel, a "Linux" system usually has: * a file system that follows the Linux Filesystem Hierarchy Standard http://www.pathname.com/fhs/. * a wide range of Unix utilities, many of which have been developed by the GNU project and the Free Software Foundation. The combination of the Linux kernel, the file system, the GNU and FSF utilities, and the other utilities are designed to achieve compliance with the POSIX (IEEE 1003.1) standard; see Section 4.3, `How source code compatible is Debian with other Unix systems?'. For more information about Linux, see What is Linux (http://www.linux.org/info/) by Linux Online (http://www.linux.org/). 1.4. Does Debian just do GNU/Linux? ----------------------------------- Currently, Debian is only available for Linux, but with Debian GNU/Hurd and Debian on BSD kernels, we have started to offer non-Linux-based OSes as a development, server and desktop platform, too. However, these non-linux ports are not officially released yet. The oldest porting effort is Debian GNU/Hurd. The Hurd is a set of servers running on top of the GNU Mach microkernel. Together they build the base for the GNU operating system. Please see http://www.gnu.org/software/hurd/ for more information about the GNU/Hurd in general, and http://www.debian.org/ports/hurd/ for more information about Debian GNU/Hurd. A second effort is the port to a BSD kernel. People are working with both the NetBSD and the FreeBSD kernels. See http://www.debian.org/ports/#nonlinux for more information about these non-linux ports. 1.5. What is the difference between Debian GNU/Linux and other Linux distributions? Why should I choose Debian over some other distribution? ---------------------------------------------------------------------------- These key features distinguish Debian from other Linux distributions: Freedom: As stated in the Debian Social Contract (http://www.debian.org/social_contract), Debian will remain 100% free. Debian is very strict about shipping truly free software. The guidelines used to determine if a work is "free" are provided in The Debian Free Software (http://www.debian.org/social_contract#guidelines). The Debian package maintenance system: The entire system, or any individual component of it, can be upgraded in place without reformatting, without losing custom configuration files, and (in most cases) without rebooting the system. Most Linux distributions available today have some kind of package maintenance system; the Debian package maintenance system is unique and particularly robust (see Chapter 7, `Basics of the Debian package management system'). Open development: Whereas other Linux distributions are developed by individuals, small, closed groups, or commercial vendors, Debian is the only major Linux distribution that is being developed cooperatively by many individuals through the Internet, in the same spirit as Linux and other free software. More than 1060 volunteer package maintainers are working on over 18200 packages and improving Debian GNU/Linux. The Debian developers contribute to the project not by writing new applications (in most cases), but by packaging existing software according to the standards of the project, by communicating bug reports to upstream developers, and by providing user support. See also additional information on how to become a contributor in Section 13.1, `How can I become a Debian software developer?'. The Universal Operating System: Debian comes with more than 18200 packages (http://packages.debian.org/stable/) and runs on 11 architectures (http://www.debian.org/ports/). This is far more than is available for any other GNU/Linux distribution. See Section 5.1, `What types of applications and development software are available for Debian GNU/Linux?' for an overview of the provided software and see Section 4.1, `On what hardware architectures/systems does Debian GNU/Linux run?' for a description of the supported hardware platforms. The Bug Tracking System: The geographical dispersion of the Debian developers required sophisticated tools and quick communication of bugs and bug-fixes to accelerate the development of the system. Users are encouraged to send bugs in a formal style, which are quickly accessible by WWW archives or via e-mail. See additional information in this FAQ on the management of the bug log in Section 12.4, `Are there logs of known bugs?'. The Debian Policy: Debian has an extensive specification of our standards of quality, the Debian Policy. This document defines the qualities and standards to which we hold Debian packages. For additional information about this, please see our web page about reasons to choose Debian (http://www.debian.org/intro/why_debian). 1.6. How does the Debian project fit in or compare with the Free Software Foundation's GNU project? ---------------------------------------------------------------------------- The Debian system builds on the ideals of free software first championed by the Free Software Foundation (http://www.gnu.org/) and in particular by Richard Stallman (http://www.stallman.org/). FSF's powerful system development tools, utilities, and applications are also a key part of the Debian system. The Debian Project is a separate entity from the FSF, however we communicate regularly and cooperate on various projects. The FSF explicitly requested that we call our system "Debian GNU/Linux", and we are happy to comply with that request. The FSF's long-standing objective is to develop a new operating system called GNU, based on Hurd (http://www.gnu.org/software/hurd/). Debian is working with FSF on this system, called Debian GNU/Hurd (http://www.debian.org/ports/hurd/). 1.7. How does one pronounce Debian and what does this word mean? ---------------------------------------------------------------- The project name is pronounced Deb'-ee-en, with a short e in Deb, and emphasis on the first syllable. This word is a contraction of the names of Debra and Ian Murdock, who founded the project. (Dictionaries seem to offer some ambiguity in the pronunciation of Ian (!), but Ian prefers ee'-en.) ------------------------------------------------------------------------------- 2. Getting and installing Debian GNU/Linux ------------------------------------------ The official document giving installation instructions is the Debian GNU/Linux Installation Guide (http://www.debian.org/releases/stable/installmanual). We'll give some additional notes about getting and installing Debian GNU/Linux here. 2.1. What is the latest version of Debian? ------------------------------------------ Currently there are three versions of Debian GNU/Linux: _release 4.0, a.k.a. the `stable' distribution or etch_ This is stable and well tested software, it changes if major security or usability fixes are incorporated. _the `testing' distribution, currently called lenny_ This is where packages that will be released as the next `stable' are placed; they've had some testing in unstable but they may not be completely fit for release yet. This distribution is updated more often than `stable', but not more often than `unstable'. _the `unstable' distribution_ This is the version currently under development; it is updated continuously. You can retrieve packages from the `unstable' archive on any Debian FTP site and use them to upgrade your system at any time, but you may not expect the system to be as usable or as stable as before - that's why it's called `_unstable_'! Please see Section 6.1, `How many Debian distributions are there?' for more information. 2.2. Are there package upgrades in `stable'? -------------------------------------------- No new functionality is added to the stable release. Once a Debian version is released and tagged `stable' it will only get security updates. That is, only packages for which a security vulnerability has been found after the release will be upgraded. All the security updates are served through security.debian.org (ftp://security.debian.org). Security updates serve one purpose: to supply a fix for a security vulnerability. They are not a method for sneaking additional changes into the stable release without going through normal point release procedure. Consequently, fixes for packages with security issues will not upgrade the software. The Debian Security Team will backport the necessary fixes to the version of the software distributed in `stable' instead. For more information related to security support please read the Security FAQ (http://www.debian.org/security/faq) or the Debian Security Manual (http://www.debian.org/doc/manuals/securing-debian-howto/). 2.3. Where/how can I get the Debian installation disks? ------------------------------------------------------- You can get the installation disks by downloading the appropriate files from one of the Debian mirrors (http://www.debian.org/mirror/list). Please refer to Debian GNU/Linux on CDs (http://www.debian.org/CD) for more information about CD (and DVD) images. 2.4. How do I install the Debian from CD-ROMs? ---------------------------------------------- Installing Debian from CD is straightforward: configure your system for booting off a CD, insert your CD, and reboot. Your system will now be running the Debian Installer. See the Debian GNU/Linux Installation Guide (http://www.debian.org/releases/stable/installmanual) for more information. 2.5. Why does the official stable released CD-ROM contain symlinks for `frozen' and `unstable'? I thought this CD contains just `stable'! ---------------------------------------------------------------------------- Official Debian CD images indeed contain symlinks like: /dists/frozen -> etch/ /dists/stable -> etch/ /dists/testing -> etch/ /dists/unstable -> etch/ so that they work when your sources.list has an entry like deb cdrom:[]/ unstable main [...] . The fact these symlinks are present does _not_ mean the image is `unstable' or `testing' or anything. Read the CD label in `/.disk/info' to find out which Debian version it contains. This information is also present in `/README.txt' on the CD. Read http://www.debian.org/releases/ to find out what the current `stable' and `testing' releases are. 2.6. Can I get and install Debian directly from a remote Internet site? ----------------------------------------------------------------------- Yes. You can boot the Debian installation system from a set of files you can download from our FTP site and its mirrors. You can download a small CD image file, create a bootable CD from it, install the basic system from it and the rest over the network. For more information please see http://www.debian.org/CD/netinst/. You can also download even smaller floppy disk image files, create bootable diskettes from them, start the installation procedure and get the rest of Debian over the network. 2.7. Are there any alternative strategies for booting the system installer? --------------------------------------------------------------------------- Yes. Apart from CD or DVD, you can install Debian GNU/Linux by booting from floppy disks, USB memory stick, directly from hard disk, or using TFTP net booting. For installing on multiple computers it's possible to do fully automatic installations. NB: not all methods are supported by all computer architectures. Once the installer has booted, the rest of the system can be downloaded over the network, or installed from local media. See the Debian GNU/Linux Installation Guide (http://www.debian.org/releases/stable/installmanual) for more information. ------------------------------------------------------------------------------- 3. Choosing a Debian distribution --------------------------------- There are many different Debian distributions. Choosing the proper Debian distribution is an important decission. This section covers some information useful for users that want to make the choice best suited for their system and also answers possible questions that might be arising during the process. It does not deal with "why you should choose Debian" but rather "which distribution of Debian". For more information on the available distributions read Section 6.1, `How many Debian distributions are there?'. 3.1. Which Debian distribution (stable/testing/unstable) is better for me? -------------------------------------------------------------------------- The answer is a bit complicated. It really depends on what you intend to do. One solution would be to ask a friend who runs Debian. But that does not mean that you cannot make an independent decision. In fact, you should be able to decide once you complete reading this chapter. * If security or stability are at all important for you: install stable. period. This is the most preferred way. * If you are a new user installing to a desktop machine, start with stable. Some of the software is quite old, but it's the least buggy environment to work in. You can easily switch to the more modern unstable once you are a little more confident. * If you are a desktop user with some experience in Linux and does not mind facing the odd bug now and then, use unstable. It has all the latest and greatest software, and bugs are usually fixed swiftly. * If you are running a server, especially one that has strong stability requirements or is exposed to the Internet, install stable. This is by far the strongest and safest choice. The following questions (hopefully) provide more detail on these choices. After reading this whole FAQ, if you still could not make a decision, stick with the stable distribution. 3.1.1. You asked me to install stable, but in stable so and so hardware is not detected/working. What should I do? ---------------------------------------------------------------------------- Try to search the web using a search engine and see if someone else is able to get it working in stable. Most of the hardware should work fine with stable. But if you have some state-of-the-art, cutting edge hardware, it might not work with stable. If this is the case, you might want to install/upgrade to unstable. For laptops, http://www.linux-on-laptops.com/ is a very good website to see if someone else is able to get it to work under Linux. The website is not specific to Debian, but is nevertheless a tremendous resource. I am not aware of any such website for desktops. Another option would be to ask in the debian-user mailing list by sending an email to debian-user@lists.debian.org . Messages can be posted to the list even without subscribing. The archives can be read through http://lists.debian.org/debian-user/ Information regarding subscribing to the list can be found at the location of archives. You are strongly encourage to post your questions on the mailing-list than on irc (http://www.debian.org/support). The mailing-list messages are archived, so solution to your problem can help others with the same issue. 3.1.2. Will there be different different versions of packages in different distributions? ---------------------------------------------------------------------------- Yes. Unstable has the most recent (latest) versions. But the packages in unstable are not well tested and might have bugs. On the other hand, stable contains old versions of packages. But this package is well tested and is less likely to have any bugs. The packages in testing fall between these two extremes. 3.1.3. The stable distributions really contains outdated packages. Just look at Kde, Gnome, Xorg or even the kernel. They are very old. Why is it so? ---------------------------------------------------------------------------- Well, you might be correct. The age of the packages at stable depends on when the last release was made. Since there is typically over 1 year between releases you might find that stable contains old versions of packages. However, they have been tested in and out. One can confidently say that the packages do not have any known severe bugs, security holes etc., in them. The packages in stable integrate seamlessly with other stable packages. These characteristics are very important for production servers which have to work 24 hours a day, 7 days a week. On the other hand, packages in testing or unstable can have hidden bugs, security holes etc., Moreover, some packages in testing and unstable might not be working as intended. Usually people working on a single desktop prefer having the latest and most modern set of packages. Unstable is the solution for this group of people. As you can see, stability and novelty are two opposing ends of the spectrum. If stability is required: install stable distribution. If you want to work with the latest packages, then install unstable. 3.1.4. If I were to decide to change to another distribution, Can I do that? ---------------------------------------------------------------------------- Yes, but it is a one way process. You can go from stable --> testing --> unstable. But the reverse direction is not "possible". So better be sure if you are planning to install/upgrade to unstable. Actually, if you are an expert and if you are willing to spend some time and if you are real careful and if you know what you are doing, then it might be possible to go from unstable to testing and then to stable. The installer scripts are not designed to do that. So in the process, your configuration files might be lost and.... 3.1.5. Could you tell me whether to install testing or unstable? ---------------------------------------------------------------- This is a rather subjective issue. There is no perfect answer but only a "wise guess" could be made while deciding between unstable and testing. My personal order of preference is Stable, Unstable and Testing. The issue is like this: * Stable is rock solid. It does not break. * Testing breaks less often than Unstable. But when it breaks, it takes a long time for things to get rectified. Sometimes this could be days and it could be months at times. * Unstable changes a lot, and it can break at any point. However, fixes get rectified in many occasions in a couple of days and it always has the latest releases of software packaged for Debian. But there are times when tracking testing would be beneficial as opposed to unstable. The author such situation due to the gcc transition from gcc3 to gcc4. He was trying to install the `labplot' package on a machine tracking unstable and it could not be installed in unstable as some of its dependencies have undergone gcc4 transition and some have not. But the package in testing was installable on a testing machine as the gcc4 transitioned packages had not "trickled down" to testing. 3.1.6. You are talking about testing being broken. What do you mean by that? ---------------------------------------------------------------------------- Sometimes, a package might not be installable through package management tools. Sometimes, a package might not be available at all, maybe it was (temporarily) removed due to bugs or unmet dependencies. Sometimes, a package installs but does not behave in the proper way. When these things happen, the distribution is said to be broken (at least for this package). 3.1.7. Why is it that testing could be broken for months? Wont the fixes introduced in unstable flow directly down into testing? ---------------------------------------------------------------------------- The bug fixes and improvements introduced in the unstable distribution trickle down to testing after a certain number of days. Let's say this threshold is 10 days. The packages in unstable go into testing only when there are no RC-bugs reported against them. If there is a RC-bug filed against a package in unstable, it will not go into testing after the 10 days. The idea is that, if the package has any problems, it would be discovered by people using unstable and will be fixed before it enters testing. This keeps the testing in an usable state for most period of the time. Overall a brilliant concept, if you ask me. But things are alwasy not so simple. Consider the following situation: * Imagine you are interested in package XYZ. * Let's assume that on June 10, the version in testing is XYZ-3.6 and in unstable it is XYZ-3.7 * After 10 days, XYZ-3.7 from unstable migrates into testing. * So on June 20, both testing and unstable have XYZ-3.7 in their repositories. * Let's say, The user of testing distribution sees that a new XYZ package is available and updates his XYZ-3.6 to XYZ-3.7 * Now on June 25, someone using testing or unstable discovers an RC bug in XYZ-3.7 and files it in the BTS. * The maintainer of XYZ fixes this bug and uploads it to unstable say on June 30. Here it is assumed that it takes 5 days for the maintainer to fix the bug and upload the new version. The number 5 should not be taken literally. It could be less or more, depending upon the severity of the RC-bug at hand. * This new version in unstable, XYZ-3.8 is scheduled to enter testing on July 10th. * But on July 5th some other person, discovers another RC-bug in XYZ-3.8 * Let's say the maintainer of XYZ fixes this new RC-bug and uploads new version of XYZ after 5 days. * So on July 10, testing has XYZ-3.7 while unstable has XYZ-3.9 * This new version XYZ-3.9 is now rescheduled to enter testing on July 20th. * Now since you are running testing, and since XYZ-3.7 is buggy, you could probably use XYZ only after July 20th. That is you essentially ended up with a broken XYZ for about one month. The situation can get much more complicated, if say, XYZ depends on 4 other packages. This could in turn lead to unusable testing distribution for months. The above scenario which is artificially created by me, can occur in the real life. But such occurrences are rare. 3.1.8. From an administrator's point of view, Which distribution requires more attention? ---------------------------------------------------------------------------- One of the main reasons many people chose Debian over other Linux distributions is that it requires very little administration. People want a system that just works. In general one can say that, stable requires very little maintenance while testing and unstable require constant maintenance from the administrator. If you are running stable, all you need to worry about is, keeping track of security updates. If you are running either testing or unstable it is a good idea to be aware of the new bugs discovered in the installed packages, new bugfixes/features introduced etc. 3.1.9. What happens when a new release is made? ----------------------------------------------- This question will not help you in choosing a Debian distribution. But sooner or later you will face this question. The stable distribution is currently etch; The next stable distribution will be called as lenny. Let's consider the particular case as to what happens when lenny is released as the new stable version. * oldstable = sarge; stable = etch; testing = lenny; unstable = sid * Unstable is always referred to as sid irrespective of whether a release is made or not. * packages constantly migrate from sid to testing (i.e. lenny). But packages in stable (i.e. etch) remain the same except for security updates. * after sometime testing becomes frozen. But it will still be called testing. At this point no new packages from unstable can migrate to testing unless they include release-critical (RC) bug fixes. * When testing is frozen, all the new bugfixes introduced, have to be manualy checked by the members of the release team. This is done to ensure that there wont be any unknown severe problems in the frozen testing. * RC bugs in 'frozen testing' are reduced to zero. * The 'frozen testing' with no rc-bugs will be released as the new stable version. In our example, this new stable release will be called as lenny. * At this stage oldstable = etch, stable = lenny. The contents of stable and 'frozen testing' are same at this point. * A new testing is forked from the current stable. * Packages start coming down from sid to testing and the Debian community will be working towards making the next stable release. 3.1.10. I have a working Desktop/cluster with Debian installed. How do I know which distribution I am running? ---------------------------------------------------------------------------- In most situations it is very easy to figure this out. Take a look at the `/etc/apt/sources.list' file. There will be an entry similar to this: deb http://ftp.us.debian.org/debian/ unstable main contrib The third field ('unstable' in the above example) indicates the Debian distribution the system is currently tracking. You can also use `lsb_release' (available in the `lsb-release' package). If you run this program in an unstable system you will get: $ lsb_release -a LSB Version: core-2.0-noarch:core-3.0-noarch:core-3.1-noarch:core-2.0-ia32:core-3.0-ia32:core-3.1-ia32 Distributor ID: Debian Description: Debian GNU/Linux unstable (sid) Release: unstable Codename: sid However, this is always not that easy. Some systems might have `sources.list' files with multiple entries corresponding to different distributions. This could happen if the administrator is tracking different packages from different Debian distributions. This is frequently referred to as apt-pinning. These systems might run a mixture of distributions. 3.1.11. I am currently tracking stable. Can I change to testing or unstable? If so, How? ---------------------------------------------------------------------------- If you are currently running stable, then in the `/etc/apt/sources.list' file the third field will be either etch or stable. You need to change this to the distribution you want to run. If you want to run testing, then change the third field of `/etc/apt/sources.list' to testing. If you want to run unstable, then change the third field to unstable. Currently testing is called lenny. So, if you change the third field of `/etc/apt/sources.list' to lenny, then also you will be running testing. But when lenny becomes stable, you will still be tracking lenny. Unstable is always called Sid. So if you change the third field of `/etc/apt/sources.list' to sid, then you will be tracking unstable. Currently Debian offers security updates for testing but not for unstable, as fixes in unstable are directly made to the main archive. So if you are running unstable make sure that you remove the lines relating to security updates in `/etc/apt/sources.list'. If there is a release notes document available for the distribution you are upgrading to (even though it has not yet been released) it would be wise to review it, as it might provide information on how you should upgrade to it. Nevertheless, once you make the above changes, you can run `aptitude update' and then install the packages that you want. Notice that installing a package from a different distribution might automatically upgrade half of your system. If you install individual packages you will end up with a system running mixed distributions. It might be best in some situations to just fully upgrade to the new distribution running `apt-get dist-upgrade', `aptitude safe-upgrade' or `aptitude full-upgrade'. Read apt's and aptitude's manual pages for more information. 3.1.12. I am currently tracking testing (lenny). What will happen when a release is made? Will I still be tracking testing or will my machine be running the new stable distribution? ---------------------------------------------------------------------------- It depends on the entries in the `/etc/apt/sources.list' file. If you are currently tracking testing, these entries are similar to either: deb http://ftp.us.debian.org/debian/ testing main or deb http://ftp.us.debian.org/debian/ lenny main If the third field in `/etc/apt/sources.list' is 'testing' then you will be tracking testing even after a release is made. So after lenny is released, you will be running a new Debian distribution which will have a different codename. Changes might not be apparent at first but will be evident as soon as new packages from unstable go over to the testing distribution. But if the third field contains 'lenny' then you will be tracking stable (since lenny will then be the new stable distribution). 3.1.13. I am still confused. What did you say I should install? --------------------------------------------------------------- If unsure, the best bet would be stable distribution. 3.2. But what about Knoppix, Linex, Ubuntu, and others? ------------------------------------------------------- They are not Debian; they are _Debian based_. Though there are many similarities and commonalities between them, there are also crucial differences. All these distributions have their own merits and are suited to some specific set of users. For more information, read the information of software distributions based on Debian (http://www.debian.org/misc/children-distros) available at the Debian website. 3.2.1. I know that Knoppix/Linex/Ubuntu/... is Debian-based. So after installing it on the hard disk, can I use 'apt' package tools on it? ---------------------------------------------------------------------------- These distributions are Debian based. But they are not Debian. You will be still able to use apt package tools by pointing the `/etc/apt/sources.list' file to these distributions' repositories. But then you are not running Debian, you are running a different distribution. They are not the same. In most situations if you stick with one distribution you should use that and not mix packages from other distributions. Many common breakages arise due to people running a distribution and trying to install Debian packages from other distributions. The fact that they use the same formatting and name (.deb) does not make them inmediately compatible. For example, Knoppix is a Linux distribution designed to be booted as a live CD where as Debian is designed to be installed on hard-disk. Knoppix is great if you want to know whether a particular hardware works, or if you want to experience how a linux system 'feels' etc., Knoppix is good for demonstration purposes while Debian is designed to run 24/7. Moreover the number of packages available, the number of architectures supported by Debian are far more greater than that of Knoppix. If you want Debian, it is best to install Debian from the get-go. Although it is possible to install Debian through other distributions, such as Knoppix, the procedure calls for expertise. If you are reading this FAQ, I would assume that you are new to both Debian and Knoppix. In that case, save yourself a lot of trouble later and install Debian right at the beginning. 3.2.2. I installed Knoppix/Linex/Ubuntu/... on my hard disk. Now I have a problem. What should I do? ---------------------------------------------------------------------------- You are advised not to use the Debian forums (either mailing lists or IRC) for help as people might advise you thinking that you are running a Debian system and the "fixes" they provide might not be suited to what you are running. They might even worsen the problem you are facing. Use the forums of the specific distribution you are using first. If you do not get help or the help you get does not fix your problem you might want to try asking in Debian forums, but keep the advise of the previous paragraph in mind. 3.2.3. I'm using Knoppix/Linex/Ubuntu/... and now I want to use Debian. How do I migrate? ---------------------------------------------------------------------------- Consider the change from a Debian-based distribution to Debian just like a change from one operating system to another one. You should make a backup of all your date and reinstall the operating system from scratch. You should not attempt to "upgrade" to Debian using the package management tools as you might end up with an unusable system. If all your user data (i.e. your `/home') is under a separate partition migrating to Debian is actually quite simple, you just have to tell the installation system to mount (but not reformat) that partition when reinstalling. Making backups of your data, as well as your previous system's configuration (i.e. `/etc/' and, maybe, `/var/') is still encouraged. ------------------------------------------------------------------------------- 4. Compatibility issues ----------------------- 4.1. On what hardware architectures/systems does Debian GNU/Linux run? ---------------------------------------------------------------------- Debian GNU/Linux includes complete source-code for all of the included programs, so it should work on all systems which are supported by the Linux kernel; see the Linux FAQ (http://en.tldp.org/FAQ/Linux-FAQ/intro.html#DOES-LINUX-RUN-ON-MY-COMPUTER) for details. The current Debian GNU/Linux release, 4.0, contains a complete, binary distribution for the following architectures: _i386_: this covers systems based on Intel and compatible processors, including Intel's 386, 486, Pentium, Pentium Pro, Pentium II (both Klamath and Celeron), and Pentium III, and most compatible processors by AMD, Cyrix and others. _amd64_: this covers systems based on AMD 64bit CPUs with AMD64 extension and all Intel CPUs with EM64T extension, and a common 64bit userspace. _alpha_: Compaq/Digital's Alpha systems. _sparc_: this covers Sun's SPARC and most UltraSPARC systems. _powerpc_: this covers some IBM/Motorola PowerPC machines, including CHRP, PowerMac and PReP machines. _arm_: ARM and StrongARM machines. _mips_: SGI's big-endian MIPS systems, Indy and Indigo2; _mipsel_: little-endian MIPS machines, Digital DECstations. _hppa_: Hewlett-Packard's PA-RISC machines (712, C3000, L2000, A500). _ia64_: Intel IA-64 ("Itanium") computers. _s390_: IBM S/390 mainframe systems. The development of binary distributions of Debian for Sparc64 (UltraSPARC native) architectures is currently underway. Support for the _m68k_ architecture was dropped in this release, because it did not meet the criteria set by the Debian Release Managers. This architecture covers Amigas and ATARIs having a Motorola 680x0 processor for x>=2; with MMU. However, the port is still active and available for installation even if not a part of this official stable release and might be reactivated for future releases. For more information on the available ports see the ports pages at the website (http://www.debian.org/ports/). For further information on booting, partitioning your drive, enabling PCMCIA (PC Card) devices and similar issues please follow the instructions given in the Installation Manual, which is available from our WWW site at http://www.debian.org/releases/stable/installmanual. 4.2. How compatible is Debian with other distributions of Linux? ---------------------------------------------------------------- Debian developers communicate with other Linux distribution creators in an effort to maintain binary compatibility across Linux distributions. Most commercial Linux products run as well under Debian as they do on the system upon which they were built. Debian GNU/Linux adheres to the Linux Filesystem Hierarchy Standard (http://www.pathname.com/fhs/). However, there is room for interpretation in some of the rules within this standard, so there may be slight differences between a Debian system and other Linux systems. Debian GNU/Linux supports software developed for the Linux Standard Base (http://www.linuxbase.org/). The LSB is a specification for allowing the same binary package to be used on multiple distributions. The Debian Etch release is Certified for LSB Release 3.1, see the Linux Foundation Certification webpage (https://www.linux-foundation.org/lsb-cert/productdir.php). Discussion and coordination of efforts towards ensuring Debian meets the requirements of the Linux Standard Base is taking place on the debian-lsb mailing list (http://lists.debian.org/debian-lsb/). 4.3. How source code compatible is Debian with other Unix systems? ------------------------------------------------------------------ For most applications Linux source code is compatible with other Unix systems. It supports almost everything that is available in System V Unix systems and the free and commercial BSD-derived systems. However in the Unix business such claim has nearly no value because there is no way to prove it. In the software development area complete compatibility is required instead of compatibility in "about most" cases. So years ago the need for standards arose, and nowadays POSIX.1 (IEEE Standard 1003.1-1990) is one of the major standards for source code compatibility in Unix-like operating systems. Linux is intended to adhere to POSIX.1, but the POSIX standards cost real money and the POSIX.1 (and FIPS 151-2) certification is quite expensive; this made it more difficult for the Linux developers to work on complete POSIX conformance. The certification costs make it unlikely that Debian will get an official conformance certification even if it completely passed the validation suite. (The validation suite is now freely available, so it is expected that more people will work on POSIX.1 issues.) Unifix GmbH (Braunschweig, Germany) developed a Linux system that has been certified to conform to FIPS 151-2 (a superset of POSIX.1). This technology was available in Unifix' own distribution called Unifix Linux 2.0 and in Lasermoon's Linux-FT. 4.4. Can I use Debian packages (".deb" files) on my Red Hat/Slackware/... Linux system? Can I use Red Hat packages (".rpm" files) on my Debian GNU/Linux system? ---------------------------------------------------------------------------- Different Linux distributions use different package formats and different package management programs. _You probably can:_ A program to unpack a Debian package onto a Linux host that is been built from a `foreign' distribution is available, and will generally work, in the sense that files will be unpacked. The converse is probably also true, that is, a program to unpack a Red Hat or Slackware package on a host that is based on Debian GNU/Linux will probably succeed in unpacking the package and placing most files in their intended directories. This is largely a consequence of the existence (and broad adherence to) the Linux Filesystem Hierarchy Standard. The Alien (http://packages.debian.org/alien) package is used to convert between different package formats. _You probably do not want to:_ Most package managers write administrative files when they are used to unpack an archive. These administrative files are generally not standardized. Therefore, the effect of unpacking a Debian package on a `foreign' host will have unpredictable (certainly not useful) effects on the package manager on that system. Likewise, utilities from other distributions might succeed in unpacking their archives on Debian systems, but will probably cause the Debian package management system to fail when the time comes to upgrade or remove some packages, or even simply to report exactly what packages are present on a system. _A better way:_ The Linux File System Standard (and therefore Debian GNU/Linux) requires that subdirectories under `/usr/local/' be entirely under the user's discretion. Therefore, users can unpack `foreign' packages into this directory, and then manage their configuration, upgrade and removal individually. 4.5. How should I install a non-Debian program? ----------------------------------------------- Files under the directory `/usr/local/' are not under the control of the Debian package management system. Therefore, it is good practice to place the source code for your program in /usr/local/src/. For example, you might extract the files for a package named "foo.tar" into the directory `/usr/local/src/foo'. After you compile them, place the binaries in `/usr/local/bin/', the libraries in `/usr/local/lib/', and the configuration files in `/usr/local/etc/'. If your programs and/or files really must be placed in some other directory, you could still store them in `/usr/local/', and build the appropriate symbolic links from the required location to its location in `/usr/local/', e.g., you could make the link ln -s /usr/local/bin/foo /usr/bin/foo In any case, if you obtain a package whose copyright allows redistribution, you should consider making a Debian package of it, and uploading it for the Debian system. Guidelines for becoming a package developer are included in the Debian Policy manual (see Section 12.1, `What other documentation exists on and for a Debian system?'). 4.6. Why can't I compile programs that require libtermcap? ---------------------------------------------------------- Debian uses the `terminfo' database and the `ncurses' library of terminal interface routes, rather than the `termcap' database and the `termcap' library. Users who are compiling programs that require some knowledge of the terminal interface should replace references to `libtermcap' with references to `libncurses'. To support binaries that have already been linked with the `termcap' library, and for which you do not have the source, Debian provides a package called `termcap-compat'. This provides both `libtermcap.so.2' and `/etc/termcap'. Install this package if the program fails to run with the error message "can't load library 'libtermcap.so.2'", or complains about a missing `/etc/termcap' file. 4.7. Why can't I install AccelX? -------------------------------- AccelX uses the `termcap' library for installation. See Section 4.6, `Why can't I compile programs that require libtermcap?' above. 4.8. Why do my old XFree 2.1 Motif applications crash? ------------------------------------------------------ You need to install the `motifnls' package, which provides the XFree-2.1 configuration files needed to allow Motif applications compiled under XFree-2.1 to run under XFree-3.1. Without these files, some Motif applications compiled on other machines (such as Netscape) may crash when attempting to copy or paste from or to a text field, and may also exhibit other problems. ------------------------------------------------------------------------------- 5. Software available in the Debian system ------------------------------------------ 5.1. What types of applications and development software are available for Debian GNU/Linux? ---------------------------------------------------------------------------- Like most Linux distributions, Debian GNU/Linux provides: * the major GNU applications for software development, file manipulation, and text processing, including gcc, g++, make, texinfo, Emacs, the Bash shell and numerous upgraded Unix utilities, * Perl, Python, Tcl/Tk and various related programs, modules and libraries for each of them, * TeX (LaTeX) and Lyx, dvips, Ghostscript, * the Xorg windowing system, which provides a networked graphical user interface for Linux, and countless X applications including the GNOME, KDE and Xfce desktop environments. * a full suite of networking applications, including servers for Internet protocols such as HTTP (WWW), FTP, NNTP (news), SMTP and POP (mail) and DNS (name servers); relational databases like PostgreSQL, MySQL; also provided are web browsers including the various Mozilla products [1], * a complete set of office applications, including the OpenOffice.org productivity suite, Gnumeric and other spreadsheets, WYSIWYG editors, calendars. More than 18040 packages, ranging from news servers and readers to sound support, FAX programs, database and spreadsheet programs, image processing programs, communications, net, and mail utilities, Web servers, and even ham-radio programs are included in the distribution. Another 560 software suites are available as Debian packages, but are not formally part of Debian due to license restrictions. [1] These have been, however, rebranded and are provided with different names due to trademark issues 5.2. Who wrote all that software? --------------------------------- For each package the _authors_ of the program(s) are credited in the file `/usr/share/doc/PACKAGE/copyright', where PACKAGE is to be substituted with the package's name. _Maintainers_ who package this software for the Debian GNU/Linux system are listed in the Debian control file (see Section 7.4, `What is a Debian control file?') that comes with each package. The Debian changelog, in `/usr/share/doc/PACKAGE/changelog.Debian.gz', mentions the people who've worked on the Debian packaging too. 5.3. How can I get a current list of programs that have been packaged for Debian? ---------------------------------------------------------------------------- A complete list is available from any of the Debian mirrors (http://www.debian.org/distrib/ftplist), in the file `indices/Maintainers'. That file includes the package names and the names and e-mails of their respective maintainers. The WWW interface to the Debian packages (http://packages.debian.org/) conveniently summarizes the packages in each of about thirty "sections" of the Debian archive. 5.4. How can I install a developer's environment to build packages? ------------------------------------------------------------------- If you want to build packages in your Debian system you will need to have a basic development environment, including a C/C++ compiler and some other essential packages. In order to install this environment you just need to install the `build-essential'. This package is a meta-package or place-holder package which depends on the standard development tools one needs to build a Debian package. Some software can, however, need additional software to be rebuilt, including library headers or additional tools such as `autoconf' or `gettext'. Debian provides many of the tools needed to build other software as Debian packages. Finding which software is precisely required can be tricky, however, unless you are planning on rebuilding Debian packages. This last task is rather easy to do, as official packages have to include a list of the additional software (besides the packages in `build-essential') needed to build the pacakge, this is known as `Build-Dependencies'. To install all the packages needed to build a given source package and then build said source package you can just run: # apt-get build-dep # apt-get source --build Notice that if you want to build the Linux kernels distributed by Debian you will want to install also the `kernel-package' package. For more information see Section 10.2, `What tools does Debian provide to build custom kernels?'. 5.5. What is missing from Debian GNU/Linux? ------------------------------------------- A list of packages which are still needed to be packaged for Debian exists, the Work-Needing and Prospective Packages list (http://www.debian.org/devel/wnpp/). For more details about adding the missing things, see Section 13.1, `How can I become a Debian software developer?'. 5.6. Why do I get "ld: cannot find -lfoo" messages when compiling programs? Why aren't there any libfoo.so files in Debian library packages? ---------------------------------------------------------------------------- Debian Policy requires that such symbolic links (to libfoo.so.x.y.z or similar) are placed in separate, development packages. Those packages are usually named libfoo-dev or libfooX-dev (presuming the library package is named libfooX, and X is a whole number). 5.7. (How) Does Debian support Java? ------------------------------------ Several _free_ implementations of Java technology are available as Debian packages, providing both Java Development Kits as well as Runtime Environments. You can write, debug and run Java programs using Debian. Running a Java applet requires a web browser with the capability to recognize and execute them. Several web browsers available in Debian, such as Mozilla or Konqueror, support Java plug-ins that enable running Java applets within them. Please refer to the Debian Java FAQ (http://www.debian.org/doc/manuals/debian-java-faq/) for more information. 5.8. How can I check that I am using a Debian system, and what version is it? ---------------------------------------------------------------------------- In order to make sure that your system has been installed from the real Debian base disks check for the existence of `/etc/debian_version' file, which contains a single one-line entry giving the version number of the release, as defined by the package `base-files'. The existence of the program `dpkg' shows that you should be able to install Debian packages on your system, but as the program has been ported to many other operating systems and architectures, this is no longer a reliable method of determining is a system Debian GNU/Linux. Users should be aware, however, that the Debian system consists of many parts, each of which can be updated (almost) independently. Each Debian "release" contains well defined and unchanging contents. Updates are separately available. For a one-line description of the installation status of package `foo', use the command `dpkg --list foo'. To view versions of all installed packages, run: dpkg -l For a more verbose description, use: dpkg --status foo 5.9. How does Debian support non-English languages? --------------------------------------------------- * Debian GNU/Linux is distributed with keymaps for nearly two dozen keyboards, and with utilities (in the `kbd' package) to install, view, and modify the tables. The installation prompts the user to specify the keyboard he will use. * Vast majority of the software we packaged supports entering non-US-ASCII characters used in other Latin languages (e.g. ISO-8859-1 or ISO-8859-2), and a number of programs support multi-byte languages such as Japanese or Chinese. * Currently, support for German-, Spanish-, Finnish-, French-, Hungarian-, Italian-, Japanese-, Korean-, Dutch-, Polish-, Portuguese-, Russian-, Turkish-, and Chinese-language manual pages is provided through the `manpages-LANG' packages (where LANG is the two-letter ISO country code). To access an NLS manual page, the user must set the shell LC_MESSAGES variable to the appropriate string. For example, in the case of the Italian-language manual pages, LC_MESSAGES needs to be set to 'italian'. The `man' program will then search for Italian manual pages under `/usr/share/man/it/'. 5.10. Where is pine? -------------------- Due to its restrictive license, it's in the non-free area. Moreover, since license does not even allow modified binaries to be distributed, you have to compile it yourself from the source and the Debian patches. The source package name is `pine'. You can use the `pine-tracker' package to be notified about when you need to upgrade. Note that there are many replacements for both pine and pico, such as `mutt' and `nano', that are located in the main section. 5.11. Where is qmail/ezmlm/djbdns? ---------------------------------- Dan J. Bernstein used to distribute all software he has written (http://cr.yp.to/software.html) with a restrictive license which does not allow modified binaries to be distributed. In november 2007 however, Bernstein said "[...] i have decided to put all of my future and [...] past software into the public domain". See FAQ from distributors (http://cr.yp.to/distributors.html) for his distribution terms. As of 2008-04, `daemontools', `djbdns' and `ucspi-tcp' are shipped with Debian lenny (in main). As of this writing (2008-04), `qmail' is not yet packaged for Debian main; see Bug #457318 (ITP qmail) (http://bugs.debian.org/457318) for the current status. As of 2008-04, `publicfile' and `ezmlm' were still not free software. For `ezmlm', there's the `ezmlm-src' package in the non-free area. 5.12. Where is a player for Flash (SWF)? ---------------------------------------- Debian ships both `gnash' and `swfdec': two free SWF movie players. 5.13. Where is Google Earth? ---------------------------- Google Earth is available for GNU/Linux from Google's web site, but is not only not Free Software, but is completely undistributable by a third party. However, `googleearth-package' (in the contrib-section) might be helpful in using this software. 5.14. Where is VoIP software? ----------------------------- Two main open protocols are used for Voice Over IP: SIP and H.323. Both are implemented by a wide variety of software in Debian main. `ekiga' is one of the popular clients. 5.15. I have a wireless network card which doesn't work with Linux. What should I do? ---------------------------------------------------------------------------- Buy one which does :) Alternatively, use `ndiswrapper' to use a driver for Windows (if you have one) on your Linux system. See the Debian Wiki ndiswapper page (http://wiki.debian.org/NdisWrapper) for more information. ------------------------------------------------------------------------------- 6. The Debian FTP archives -------------------------- 6.1. How many Debian distributions are there? --------------------------------------------- There are three major distributions: the "stable" distribution, the "testing" distribution, and the "unstable" distribution. The "testing" distribution is sometimes `frozen' (see Section 6.5.1, `What about "testing"? How is it `frozen'?'). Next to these, there is the "oldstable" distribution (that's just the one from before "stable"), and the "experimental" distribution. Experimental is used for packages which are still being developed, and with a high risk of breaking your system. It's used by developers who'd like to study and test bleeding edge software. Users shouldn't be using packages from here, because they can be dangerous and harmful even for the most experienced people. See Chapter 3, `Choosing a Debian distribution' for help when choosing a Debian distribution. 6.2. What are all those names like etch, lenny, etc.? ----------------------------------------------------- They are just "codenames". When a Debian distribution is in the development stage, it has no version number but a codename. The purpose of these codenames is to make easier the mirroring of the Debian distributions (if a real directory like `unstable' suddenly changed its name to `stable', a lot of stuff would have to be needlessly downloaded again). Currently, `stable' is a symbolic link to `etch' (i.e. Debian GNU/Linux 4.0) and `testing' is a symbolic link to `lenny'. This means that `etch' is the current stable distribution and `lenny' is the current testing distribution. `unstable' is a permanent symbolic link to `sid', as `sid' is always the unstable distribution (see Section 6.3, `What about "sid"?'). 6.2.1. Which other codenames have been used in the past? -------------------------------------------------------- Other codenames that have been already used are: `buzz' for release 1.1, `rex' for release 1.2, `bo' for releases 1.3.x, `hamm' for release 2.0, `slink' for release 2.1, `potato' for release 2.2, `woody' for release 3.0, `sarge' for release 3.1, and `etch' for release 4.0. 6.2.2. Where do these codenames come from? ------------------------------------------ So far they have been characters taken from the movie "Toy Story" by Pixar. * _buzz_ (Buzz Lightyear) was the spaceman, * _rex_ was the tyrannosaurus, * _bo_ (Bo Peep) was the girl who took care of the sheep, * _hamm_ was the piggy bank, * _slink_ (Slinky Dog (R)) was the toy dog, * _potato_ was, of course, Mr. Potato (R), * _woody_ was the cowboy, * _sarge_ was the sergeant of the Green Plastic Army Men, * _etch_ was the toy blackboard (Etch-a-Sketch (R)), * _lenny_ was the binoculars. * _sid_ was the boy next door who destroyed toys. 6.3. What about "sid"? ---------------------- _sid_ or _unstable_ is the place where most of the packages are initially uploaded. It will never be released directly, because packages which are to be released will first have to be included in _testing_, in order to be released in _stable_ later on. sid contains packages for both released and unreleased architectures. The name "sid" also comes from the "Toy Story" animated motion picture: Sid was the boy next door who destroyed toys :-) [1] [1] When the present-day sid did not exist, the FTP site organization had one major flaw: there was an assumption that when an architecture is created in the current unstable, it will be released when that distribution becomes the new stable. For many architectures that isn't the case, with the result that those directories had to be moved at release time. This was impractical because the move would chew up lots of bandwidth. The archive administrators worked around this problem for several years by placing binaries for unreleased architectures in a special directory called "sid". For those architectures not yet released, the first time they were released there was a link from the current stable to sid, and from then on they were created inside the unstable tree as normal. This layout was somewhat confusing to users. With the advent of package pools (see Section 6.10, `What's in the `pool' directory?'), binary packages began to be stored in a canonical location in the pool, regardless of the distribution, so releasing a distribution no longer causes large bandwidth consumption on the mirrors (there is, however, a lot of gradual bandwidth consumption throughout the development process). 6.4. What does the stable directory contain? -------------------------------------------- * stable/main/: This directory contains the packages which formally constitute the most recent release of the Debian GNU/Linux system. These packages all comply with the Debian Free Software Guidelines (http://www.debian.org/social_contract#guidelines), and are all freely usable and distributable. * stable/non-free/: This directory contains packages distribution of which is restricted in a way that requires that distributors take careful account of the specified copyright requirements. For example, some packages have licenses which prohibit commercial distribution. Others can be redistributed but are in fact shareware and not free software. The licenses of each of these packages must be studied, and possibly negotiated, before the packages are included in any redistribution (e.g., in a CD-ROM). * stable/contrib/: This directory contains packages which are DFSG-free and _freely distributable_ themselves, but somehow depend on a package that is _not_ freely distributable and thus available only in the non-free section. 6.5. What does the testing distribution contain? ------------------------------------------------ Packages are installed into the `testing' directory after they have undergone some degree of testing in unstable. They must be in sync on all architectures where they have been built and mustn't have dependencies that make them uninstallable; they also have to have fewer release-critical bugs than the versions currently in testing. This way, we hope that `testing' is always close to being a release candidate. More information about the status of "testing" in general and the individual packages is available at http://www.debian.org/devel/testing. 6.5.1. What about "testing"? How is it `frozen'? ------------------------------------------------ When the "testing" distribution is mature enough, the release manager starts `freezing' it. The normal propagation delays are increased to ensure that as little as possible new bugs from "unstable" enter "testing". After a while, the "testing" distribution becomes truly `frozen'. This means that all new packages that are to propagate to the "testing" are held back, unless they include release-critical bug fixes. The "testing" distribution can also remain in such a deep freeze during the so-called `test cycles', when the release is imminent. We keep a record of bugs in the "testing" distribution that can hold off a package from being released, or bugs that can hold back the whole release. For details, please see current testing release information (http://www.debian.org/releases/testing/). Once that bug count lowers to maximum acceptable values, the frozen "testing" distribution is declared "stable" and released with a version number. With each new release, the previous "stable" distribution becomes obsolete and moves to the archive. For more information please see Debian archive (http://www.debian.org/distrib/archive). 6.6. What does the unstable distribution contain? ------------------------------------------------- The `unstable' directory contains a snapshot of the current development system. Users are welcome to use and test these packages, but are warned about their state of readiness. The advantage of using the unstable distribution is that you are always up-to-date with the latest in GNU/Linux software industry, but if it breaks: you get to keep both parts :-) There are also main, contrib and non-free subdirectories in `unstable', separated on the same criteria as in `stable'. 6.7. What are all those directories at the Debian FTP archives? --------------------------------------------------------------- The software that has been packaged for Debian GNU/Linux is available in one of several directory trees on each Debian mirror site. The `dists' directory is short for "distributions", and it is the canonical way to access the currently available Debian releases (and pre-releases). The `pool' directory contains the actual packages, see Section 6.10, `What's in the `pool' directory?'. There are the following supplementary directories: _/tools/_: DOS utilities for creating boot disks, partitioning your disk drive, compressing/decompressing files, and booting Linux. _/doc/_: The basic Debian documentation, such as this FAQ, the bug reporting system instructions, etc. _/indices/_: various indices of the site (the Maintainers file and the override files). _/project/_: mostly developer-only materials and some miscellaneous files. 6.8. What are all those directories inside `dists/stable/main'? --------------------------------------------------------------- Within each of the major directory trees[1], there are three sets of subdirectories containing index files. There's one set of `binary-' subdirectories which contain index files for binary packages of each available computer architecture, for example `binary-i386' for packages which execute on Intel x86 PC machines or `binary-sparc' for packages which execute on Sun SPARCStations. The complete list of available architectures for each release is available at the release's web page (http://www.debian.org/releases/). For the current release, please see Section 4.1, `On what hardware architectures/systems does Debian GNU/Linux run?'. The index files in binary-* are called Packages(.gz, .bz2) and they include a summary of each binary package that is included in that distribution. The actual binary packages reside in the top level `pool' directory. Furthermore, there's a subdirectory called source/ which contains index files for source packages included in the distribution. The index file is called Sources(.gz, .bz2). Last but not least, there's a set of subdirectories meant for the installation system index files, they are at `debian-installer/binary-'. [1] `dists/stable/main', `dists/stable/contrib', `dists/stable/non-free', and `dists/unstable/main/', etc. 6.9. Where is the source code? ------------------------------ Source code is included for everything in the Debian system. Moreover, the license terms of most programs in the system _require_ that source code be distributed along with the programs, or that an offer to provide the source code accompany the programs. The source code is distributed in the `pool' directory (see Section 6.10, `What's in the `pool' directory?') together with all the architecture-specific binary directories. To retrieve the source code without having to be familiar with the structure of the FTP archive, try a command like `apt-get source mypackagename'. Some packages are only distributed as source code due to the restrictions in their licenses. Notably, one such package is `pine', see Section 5.10, `Where is pine?' for more information. Source code may or may not be available for packages in the "contrib" and "non-free" directories, which are not formally part of the Debian system. 6.10. What's in the `pool' directory? ------------------------------------- Packages are kept in a large `pool', structured according to the name of the source package. To make this manageable, the pool is subdivided by section (`main', `contrib' and `non-free') and by the first letter of the source package name. These directories contain several files: the binary packages for each architecture, and the source packages from which the binary packages were generated. You can find out where each package is placed by executing a command like `apt-cache showsrc mypackagename' and looking at the `Directory:' line. For example, the `apache' packages are stored in `pool/main/a/apache/'. Additionally, since there are so many `lib*' packages, these are treated specially: for instance, libpaper packages are stored in `pool/main/libp/libpaper/'. [1] [1] Historically, packages were kept in the subdirectory of `dists' corresponding to which distribution contained them. This turned out to cause various problems, such as large bandwidth consumption on mirrors when major changes were made. This was fixed with the introduction of the package pool. The `dists' directories are still used for the index files used by programs like `apt'. 6.11. What is "incoming"? ------------------------- After a developer uploads a package, it stays for a short while in the "incoming" directory before it is checked that it's genuine and allowed into the archive. Usually nobody should install things from this place. However, in some rare cases of emergency, the incoming directory is available at http://incoming.debian.org/. You can manually fetch packages, check the GPG signature and MD5sums in the .changes and .dsc files, and then install them. 6.12. How do I set up my own apt-able repository? ------------------------------------------------- If you have built some private Debian packages which you'd like to install using the standard Debian package management tools, you can set up your own apt-able package archive. This is also useful if you'd like to share your Debian packages while these are not distributed by the Debian project. Instructions on how to do this are given in the Debian Repository HOWTO (http://www.debian.org/doc/manuals/repository-howto/repository-howto). ------------------------------------------------------------------------------- 7. Basics of the Debian package management system ------------------------------------------------- This chapter touches on some lower level internals of Debian package management. If you're interested mainly in _usage_ of the relevant tools, skip to chapters Chapter 8, `The Debian package management tools' and/or Chapter 9, `Keeping your Debian system up-to-date'. 7.1. What is a Debian package? ------------------------------ Packages generally contain all of the files necessary to implement a set of related commands or features. There are two types of Debian packages: * _Binary packages_, which contain executables, configuration files, man/info pages, copyright information, and other documentation. These packages are distributed in a Debian-specific archive format (see Section 7.2, `What is the format of a Debian binary package?'); they are usually distinguished by having a '.deb' file extension. Binary packages can be unpacked using the Debian utility `dpkg' (possibly via a frontend like `aptitude'); details are given in its manual page. * _Source packages_, which consist of a `.dsc' file describing the source package (including the names of the following files), a `.orig.tar.gz' file that contains the original unmodified source in gzip-compressed tar format and usually a `.diff.gz' file that contains the Debian-specific changes to the original source. The utility `dpkg-source' packs and unpacks Debian source archives; details are provided in its manual page. (The program `apt-get' can get used a frontend for `dpkg-source'.) Installation of software by the package system uses "dependencies" which are carefully designed by the package maintainers. These dependencies are documented in the `control' file associated with each package. For example, the package containing the GNU C compiler (`gcc') "depends" on the package `binutils' which includes the linker and assembler. If a user attempts to install `gcc' without having first installed `binutils', the package management system (dpkg) will send an error message that it also needs `binutils', and stop installing `gcc'. (However, this facility can be overridden by the insistent user, see dpkg(8).) See more in Section 7.9, `What is meant by saying that a package _Depends_, _Recommends_, _Suggests_, _Conflicts_, _Replaces_ or _Provides_ another package?' below. Debian's packaging tools can be used to: * manipulate and manage packages or parts of packages, * administer local overrides of files in a package, * aid developers in the construction of package archives, and * aid users in the installation of packages which reside on a remote FTP site. 7.2. What is the format of a Debian binary package? --------------------------------------------------- A Debian "package", or a Debian archive file, contains the executable files, libraries, and documentation associated with a particular suite of program or set of related programs. Normally, a Debian archive file has a filename that ends in `.deb'. The internals of this Debian binary packages format are described in the deb(5) manual page. This internal format is subject to change (between major releases of Debian GNU/Linux), therefore please always use dpkg-deb(1) if you need to do lowlevel manipulations on `.deb' files. 7.3. Why are Debian package file names so long? ----------------------------------------------- The Debian binary package file names conform to the following convention: _-_.deb Note that `foo' is supposed to be the package name. As a check, one can learn the package name associated with a particular Debian archive file (.deb file) in one of these ways: * inspect the "Packages" file in the directory where it was stored at a Debian FTP archive site. This file contains a stanza describing each package; the first field in each stanza is the formal package name. * use the command `dpkg --info foo_VVV-RRR_AAA.deb' (where VVV, RRR and AAA are the version, revision and architecture of the package in question, respectively). This displays, among other things, the package name corresponding to the archive file being unpacked. The `VVV' component is the version number specified by the upstream developer. There are no standards in place here, so the version number may have formats as different as "19990513" and "1.3.8pre1". The `RRR' component is the Debian revision number, and is specified by the Debian developer (or an individual user if he chooses to build the package himself). This number corresponds to the revision level of the Debian package, thus, a new revision level usually signifies changes in the Debian Makefile (`debian/rules'), the Debian control file (`debian/control'), the installation or removal scripts (`debian/p*'), or in the configuration files used with the package. The `AAA' component identifies the processor for which the package was built. This is commonly `i386', which refers to chips compatible to Intel's 386 or later versions. For other possibilities review Debian's FTP directory structure at Section 6.7, `What are all those directories at the Debian FTP archives?'. For details, see the description of "Debian architecture" in the manual page dpkg-architecture(1). 7.4. What is a Debian control file? ----------------------------------- Specifics regarding the contents of a Debian control file are provided in the Debian Policy Manual, section 5, see Section 12.1, `What other documentation exists on and for a Debian system?'. Briefly, a sample control file is shown below for the Debian package hello: Package: hello Priority: optional Section: devel Installed-Size: 45 Maintainer: Adam Heath Architecture: i386 Version: 1.3-16 Depends: libc6 (>= 2.1) Description: The classic greeting, and a good example The GNU hello program produces a familiar, friendly greeting. It allows nonprogrammers to use a classic computer science tool which would otherwise be unavailable to them. . Seriously, though: this is an example of how to do a Debian package. It is the Debian version of the GNU Project's `hello world' program (which is itself an example for the GNU Project). The Package field gives the package name. This is the name by which the package can be manipulated by the package tools, and usually similar to but not necessarily the same as the first component string in the Debian archive file name. The Version field gives both the upstream developer's version number and (in the last component) the revision level of the Debian package of this program as explained in Section 7.3, `Why are Debian package file names so long?'. The Architecture field specifies the chip for which this particular binary was compiled. The Depends field gives a list of packages that have to be installed in order to install this package successfully. The Installed-Size indicates how much disk space the installed package will consume. This is intended to be used by installation front-ends in order to show whether there is enough disk space available to install the program. The Section line gives the "section" where this Debian package is stored at the Debian FTP sites. The Priority indicates how important is this package for installation, so that semi-intelligent software like dselect or aptitude can sort the package into a category of e.g. packages optionally installed. See Section 7.7, `What is an _Essential_, _Required_, _Important_, _Standard_, _Optional_, or _Extra_ package?'. The Maintainer field gives the e-mail address of the person who is currently responsible for maintaining this package. The Description field gives a brief summary of the package's features. For more information about all possible fields a package can have, please see the Debian Policy Manual, section 5., "Control files and their fields". 7.5. What is a Debian conffile? ------------------------------- Conffiles is a list of configuration files (usually placed in `/etc') that the package management system will not overwrite when the package is upgraded. This ensures that local values for the contents of these files will be preserved, and is a critical feature enabling the in-place upgrade of packages on a running system. To determine exactly which files are preserved during an upgrade, run: dpkg --status package And look under "Conffiles:". 7.6. What is a Debian preinst, postinst, prerm, and postrm script? ------------------------------------------------------------------ These files are executable scripts which are automatically run before or after a package is installed. Along with a file named `control', all of these files are part of the "control" section of a Debian archive file. The individual files are: preinst This script executes before that package will be unpacked from its Debian archive (".deb") file. Many 'preinst' scripts stop services for packages which are being upgraded until their installation or upgrade is completed (following the successful execution of the 'postinst' script). postinst This script typically completes any required configuration of the package `foo' once `foo' has been unpacked from its Debian archive (".deb") file. Often, 'postinst' scripts ask the user for input, and/or warn the user that if he accepts default values, he should remember to go back and re-configure that package as the situation warrants. Many 'postinst' scripts then execute any commands necessary to start or restart a service once a new package has been installed or upgraded. prerm This script typically stops any daemons which are associated with a package. It is executed before the removal of files associated with the package. postrm This script typically modifies links or other files associated with `foo', and/or removes files created by the package. (Also see Section 7.8, `What is a Virtual Package?'.) Currently all of the control files can be found in directory `/var/lib/dpkg/info'. The files relevant to package `foo' begin with the name "foo" and have file extensions of "preinst", "postinst", etc., as appropriate. The file `foo.list' in that directory lists all of the files that were installed with the package `foo'. (Note that the location of these files is a dpkg internal; you should not rely on it.) 7.7. What is an _Essential_, _Required_, _Important_, _Standard_, _Optional_, or _Extra_ package? ---------------------------------------------------------------------------- Each Debian package is assigned a _priority_ by the distribution maintainers, as an aid to the package management system. The priorities are: * _Required_: packages that are necessary for the proper functioning of the system. This includes all tools that are necessary to repair system defects. You must not remove these packages or your system may become totally broken and you may probably not even be able to use dpkg to put things back. Systems with only the Required packages are probably unusable, but they do have enough functionality to allow the sysadmin to boot and install more software. * _Important_ packages should be found on any Unix-like system. Other packages which the system will not run well or be usable without will be here. This does _NOT_ include Emacs or X or TeX or any other large applications. These packages only constitute the bare infrastructure. * _Standard_ packages are standard on any Linux system, including a reasonably small but not too limited character-mode system. Tools are included to be able to browse the web (using w3m), send e-mail (with mutt) and download files from FTP servers. This is what will install by default if users do not select anything else. It does not include many large applications, but it does include the Python interpreter and some server software like OpenSSH (for remote administration), Exim (for mail delivery, although it can be configured for local delivery only), an identd server (pidentd) and the RPC portmapper (`portmap'). It also includes some common generic documentation that most users will find helpful. * _Optional_ packages include all those that you might reasonably want to install if you did not know what it was, or do not have specialized requirements. This includes X, a full TeX distribution, and lots of applications. * _Extra_: packages that either conflict with others with higher priorities, are only likely to be useful if you already know what they are, or have specialized requirements that make them unsuitable for "Optional". If you do a default Debian installation all the packages of priority _Standard_ or higher will be installed in your system. If you select pre-defined tasks you will get lower priority packages too. Additionally, some packages are marked as _Essential_ since they are absolutely necessary for the proper functioning of the system. The package management tools will refuse to remove these. 7.8. What is a Virtual Package? ------------------------------- A virtual package is a generic name that applies to any one of a group of packages, all of which provide similar basic functionality. For example, both the `tin' and `trn' programs are news readers, and should therefore satisfy any dependency of a program that required a news reader on a system, in order to work or to be useful. They are therefore both said to provide the "virtual package" called `news-reader'. Similarly, `smail' and `sendmail' both provide the functionality of a mail transport agent. They are therefore said to provide the virtual package, "mail transport agent". If either one is installed, then any program depending on the installation of a `mail-transport-agent' will be satisfied by the existence of this virtual package. Debian provides a mechanism so that, if more than one package which provide the same virtual package is installed on a system, then system administrators can set one as the preferred package. The relevant command is `update-alternatives', and is described further in Section 11.10, `Some users like mawk, others like gawk; some like vim, others like elvis; some like trn, others like tin; how does Debian support diversity?'. 7.9. What is meant by saying that a package _Depends_, _Recommends_, _Suggests_, _Conflicts_, _Replaces_ or _Provides_ another package? ---------------------------------------------------------------------------- The Debian package system has a range of package "dependencies" which are designed to indicate (in a single flag) the level at which Program A can operate independently of the existence of Program B on a given system: * Package A _depends_ on Package B if B absolutely must be installed in order to run A. In some cases, A depends not only on B, but on a version of B. In this case, the version dependency is usually a lower limit, in the sense that A depends on any version of B more recent than some specified version. * Package A _recommends_ Package B, if the package maintainer judges that most users would not want A without also having the functionality provided by B. * Package A _suggests_ Package B if B contains files that are related to (and usually enhance) the functionality of A. * Package A _conflicts_ with Package B when A will not operate if B is installed on the system. Most often, conflicts are cases where A contains files which are an improvement over those in B. "Conflicts" are often combined with "replaces". * Package A _replaces_ Package B when files installed by B are removed and (in some cases) over-written by files in A. * Package A _provides_ Package B when all of the files and functionality of B are incorporated into A. This mechanism provides a way for users with constrained disk space to get only that part of package A which they really need. More detailed information on the use of each these terms can be found in the Policy manual. 7.10. What is meant by Pre-Depends? ----------------------------------- "Pre-Depends" is a special dependency. In the case of most packages, `dpkg' will unpack its archive file (i.e., its `.deb' file) independently of whether or not the files on which it depends exist on the system. Simplistically, unpacking means that `dpkg' will extract the files from the archive file that were meant to be installed on your file system, and put them in place. If those packages _depend_ on the existence of some other packages on your system, `dpkg' will refuse to complete the installation (by executing its "configure" action) until the other packages are installed. However, for some packages, `dpkg' will refuse even to unpack them until certain dependencies are resolved. Such packages are said to "Pre-depend" on the presence of some other packages. The Debian project provided this mechanism to support the safe upgrading of systems from `a.out' format to `ELF' format, where the _order_ in which packages were unpacked was critical. There are other large upgrade situations where this method is useful, e.g. the packages with the required priority and their LibC dependency. As before, more detailed information about this can be found in the Policy manual. 7.11. What is meant by _unknown_, _install_, _remove_, _purge_ and _hold_ in the package status? ---------------------------------------------------------------------------- These "want" flags tell what the user wanted to do with a package (as indicated either by the user's actions in the "Select" section of `dselect', or by the user's direct invocations of `dpkg'). Their meanings are: * unknown - the user has never indicated whether he wants the package * install - the user wants the package installed or upgraded * remove - the user wants the package removed, but does not want to remove any existing configuration files. * purge - the user wants the package to be removed completely, including its configuration files. * hold - the user wants this package not to be processed, i.e., he wants to keep the current version with the current status whatever that is. 7.12. How do I put a package on hold? ------------------------------------- There are three ways of holding back packages, with dpkg, aptitude or with dselect. With dpkg, you have to export the list of package selections, with: dpkg --get-selections \* > selections.txt Then edit the resulting file `selections.txt', change the line containing the package you wish to hold, e.g. `libc6', from this: libc6 install to this: libc6 hold Save the file, and reload it into dpkg database with: dpkg --set-selections < selections.txt With aptitude, you can hold a package using aptitude hold package_name and remove the hold with aptitude unhold package_name With dselect, you have to enter the [S]elect screen, find the package you wish to hold in its present state, and press the `=' key (or `H'). The changes will go live immediately after you exit the [S]elect screen. 7.13. How do I install a source package? ---------------------------------------- Debian source packages can't actually be "installed", they are just unpacked in whatever directory you want to build the binary packages they produce. Source packages are distributed on most of the same mirrors where you can obtain the binary packages. If you set up your APT's sources.list(5) to include the appropriate "deb-src" lines, you'll be able to easily download any source packages by running apt-get source foo To help you in actually building the source package, Debian source package provide the so-called build-dependencies mechanism. This means that the source package maintainer keeps a list of other packages that are required to build their package. To see how this is useful, run apt-get build-dep foo before building the source. 7.14. How do I build binary packages from a source package? ----------------------------------------------------------- The preferred way to do this is by using various wrapper tools. We'll show how it's done using the `devscripts' tools. Install this package if you haven't done so already. Now, first get the source package: apt-get source foo and change to the source tree: cd foo-* Then install needed build-dependencies (if any): sudo apt-get build-dep foo Then create a dedicated version of your own build (so that you won't get confused later when Debian itself releases a new version) dch -l local 'Blah blah blah' And finally build your package debuild -us -uc If everything worked out fine, you should now be able to install your package by running sudo dpkg -i ../*.deb If you prefer to do things manually, and don't want to use `devscripts', follow this procedure: You will need all of foo_*.dsc, foo_*.tar.gz and foo_*.diff.gz to compile the source (note: there is no .diff.gz for some packages that are native to Debian). Once you have them (Section 7.13, `How do I install a source package?'), if you have the `dpkg-dev' package installed, the following command: dpkg-source -x foo_version-revision.dsc will extract the package into a directory called `foo-version'. If you want just to compile the package, you may cd into `foo-version' directory and issue the command dpkg-buildpackage -rfakeroot -b to build the package (note that this also requires the `fakeroot' package), and then dpkg -i ../foo_version-revision_arch.deb to install the newly-built package(s). 7.15. How do I create Debian packages myself? --------------------------------------------- For a more detailed description on this, read the New Maintainers' Guide, available in the `maint-guide' package, or at http://www.debian.org/doc/devel-manuals#maint-guide. ------------------------------------------------------------------------------- 8. The Debian package management tools -------------------------------------- 8.1. What programs does Debian provide for managing its packages? ----------------------------------------------------------------- There are multiple tools that are used to manage Debian packages, from graphic or text-based interfaces to the low level tools used to install packages. All the available tools rely on the lower level tools to properly work and are presented here in decreasing complexity level. It is important to understand that the higher level package management tools such as `aptitude' or `dselect' rely on `apt' which, itself, relies on `dpkg' to manage the packages in the system. See the APT HOWTO (http://www.debian.org/doc/manuals/apt-howto/) for more information about the Debian package management utilities. This document is available in various languages and formats, see the APT HOWTO entry on the DDP Users' Manuals overview (http://www.debian.org/doc/user-manuals#apt-howto). 8.1.1. dpkg ----------- This is the main package management program. `dpkg' can be invoked with many options. Some common uses are: * Find out all the options: `dpkg --help'. * Print out the control file (and other information) for a specified package: `dpkg --info foo_VVV-RRR.deb' * Install a package (including unpacking and configuring) onto the file system of the hard disk: `dpkg --install foo_VVV-RRR.deb'. * Unpack (but do not configure) a Debian archive into the file system of the hard disk: `dpkg --unpack foo_VVV-RRR.deb'. Note that this operation does _not_ necessarily leave the package in a usable state; some files may need further customization to run properly. This command removes any already-installed version of the program and runs the preinst (see Section 7.6, `What is a Debian preinst, postinst, prerm, and postrm script?') script associated with the package. * Configure a package that already has been unpacked: `dpkg --configure foo'. Among other things, this action runs the postinst (see Section 7.6, `What is a Debian preinst, postinst, prerm, and postrm script?') script associated with the package. It also updates the files listed in the `conffiles' for this package. Notice that the 'configure' operation takes as its argument a package name (e.g., foo), _not_ the name of a Debian archive file (e.g., foo_VVV-RRR.deb). * Extract a single file named "blurf" (or a group of files named "blurf*" from a Debian archive: `dpkg --fsys-tarfile foo_VVV-RRR.deb | tar -xf - blurf*' * Remove a package (but not its configuration files): `dpkg --remove foo'. * Remove a package (including its configuration files): `dpkg --purge foo'. * List the installation status of packages containing the string (or regular expression) "foo*": `dpkg --list 'foo*''. 8.1.2. APT ---------- APT is the _Advanced Package Tool_ and provides the `apt-get' program. `apt-get' provides a simple way to retrieve and install packages from multiple sources using the command line. Unlike `dpkg', `apt-get' does not understand .deb files, it works with the packages proper name and can only install .deb archives from a source specified in `/etc/apt/sources.list'. `apt-get' will call `dpkg' directly after downloading the .deb archives[1] from the configured sources. Some common ways to use `apt-get' are: * To update the list of package known by your system, you can run: apt-get update (you should execute this regularly to update your package lists) * To upgrade all the packages on your system (without installing extra packages or removing packages), run: apt-get upgrade * To install the package and all its dependencies, run: apt-get install foo * To remove the foo package from your system, run: apt-get remove foo * To remove the foo package and its configuration files from your system, run: apt-get --purge remove foo * To upgrade all the packages on your system, and, if needed for a package upgrade, installing extra packages or removing packages, run: apt-get dist-upgrade (The command `upgrade' keeps a package at its installed obsolete version if upgrading would need an extra package to be installed, for a new dependency to be satisfied. The `dist-upgrade' command is less conservative.) Note that you must be logged in as root to perform any commands that modify the system packages. The apt tool suite also includes the `apt-cache' tool to query the package lists. You can use it to find packages providing specific functionality through simple text or regular expression queries and through queries of dependencies in the package management system. Some common ways to use `apt-cache' are: * To find packages whose description contain : apt-cache search * To print the detailed information of a package: apt-cache show * To print the packages a given package depends on: apt-cache depends * To print detailed information of the versions available for a package and the packages that reverse-depends on it: apt-cache showpkg For more information, install the `apt' package and read apt-get(8), sources.list(5) and install the `apt-doc' package and read `/usr/share/doc/apt-doc/guide.html/index.html'. [1] Notice that there are ports that make this tool available with other package management systems, like Red Hat package manager, also known as `rpm' 8.1.3. aptitude --------------- `aptitude' is a package manager for Debian GNU/Linux systems that provides a frontend to the apt package management infrastructure. `aptitude' is a text-based interface using the curses library, it can be used to perform management tasks in a fast and easy way. `aptitude' provides the functionality of `dselect' and `apt-get', as well as many additional features not found in either program: * `aptitude' offers access to all versions of a package. * `aptitude' logs all its actions in `/var/log/aptitude'. * `aptitude' makes it easy to keep track of obsolete software by listing it under "Obsolete and Locally Created Packages". * `aptitude' includes a fairly powerful system for searching particular packages and limiting the package display. Users familiar with `mutt' will pick up quickly, as `mutt' was the inspiration for the expression syntax. * `aptitude' tracks which packages have been installed due to dependencies and removes them automatically when the packages that needed them are removed from the system. * `aptitude' can automatically install _Recommended:_ packages[1]. * `aptitude' can be used to install the predefined tasks available. For more information see Section 8.1.5, `tasksel'. * `aptitude' in full screen mode has `su' functionality embedded and can be run by a normal user. It will call `su' (and ask for the root password, if any) when you really need administrative privileges You can use `aptitude' through a visual interface (simply run `aptitude') or directly from the command line. The command line syntax used is very similar to the one used in `apt-get'. For example, to install the package, you can run `aptitude install '. Note that `aptitude' is the preferred program for package management from console both for package installations and package or system upgrades. For more informations, read the manual page aptitude(8) and install the `aptitude-doc' package. [1] Although this can also lead to systems with more packages installed than they actually need to work. 8.1.4. synaptic --------------- `synaptic' is a graphical package manager. It enables you to install, upgrade and remove software packages in a user friendly way. Next to all features offered by aptitude, it also has a feature for editing the list of used repositories, and supports browsing all available documentation related to a package. See the Synaptic Website (http://www.nongnu.org/synaptic/) for more information. 8.1.5. tasksel -------------- When you want to perform a specific task it might be difficult to find the appropiate suite of packages that fill your need. The Debian developers have defined `tasks', a task is a collection of several individual Debian packages all related to a specific activity. Tasks can be installed through the `tasksel' program or through `aptitude'. The Debian installer will typically install automaticaly the task associated with a standard system and a desktop environment. The specific desktop environment installed will depend on the CD/DVD media used, most commonly it will be the GNOME desktop (`gnome-desktop' task). Also, depending on your selections throughout the installation process, tasks might be automatically installed in your system. For example, if you selected a language, the task associated with it will be installed automatically too and if you are running in a laptop system the installer recognises the `laptop' task will be installed too. 8.1.6. Other package management tools ------------------------------------- 8.1.6.1. dselect ---------------- This program is a menu-driven interface to the Debian package management system. For woody and earlier releases, this was the main package management interface for for first-time installations, but currently users are encouraged to use `aptitude' instead. Some users might feel more comfortable using `aptitude' and it is also recommended over `dselect' for large-scale upgrades. For more information on `aptitude' please see Section 8.1.3, `aptitude'. `dselect' can: * guide the user as he/she chooses among packages to install or remove, ensuring that no packages are installed that conflict with one another, and that all packages required to make each package work properly are installed; * warn the user about inconsistencies or incompatibilities in their selections; * determine the order in which the packages must be installed; * automatically perform the installation or removal; and * guide the user through whatever configuration process are required for each package. `dselect' begins by presenting the user with a menu of 7 items, each of which is a specific action. The user can select one of the actions by using the arrow keys to move the highlighter bar, then pressing the __ key to select the highlighted action. What the user sees next depends on the action he selected. If he selects any option but `Access' or `Select', then `dselect' will simply proceed to execute the specified action: e.g., if the user selected the action `Remove', then dselect would proceed to remove all of the files selected for removal when the user last chose the `Select' action. Both the `Access' menu item and the `Select' menu item lead to additional menus. In both cases, the menus are presented as split screens; the top screen gives a scrollable list of choices, while the bottom screen gives a brief explanation ("info") for each choice. Extensive on-line help is available, use the '?' key to get to a help screen at any time. The order in which the actions are presented in the first `dselect' menu represents the order in which a user would normally choose `dselect' to install packages. However, a user can pick any of the main menu choices as often as needed (including not at all, depending on what one wants to do). * Begin by choosing an _Access Method_. This is the method by which the user plans on accessing Debian packages; e.g., some users have Debian packages available on CD-ROM, while others plan to fetch them using anonymous FTP. The selected "Access Method" is stored after `dselect' exits, so if it does not change, then this option need not be invoked again. * Then _Update_ the list of available packages. To do this, `dselect' reads the file "Packages.gz" which should be included in the top level of the directory where the Debian packages to be installed are stored. (But if it is not there, `dselect' will offer to make it for you.) * _Select_ specific packages for installation on his system. After choosing this menu item, the user is first presented with a full screen of help (unless the `--expert' command line option was used). Once the user exits the Help screen, he sees the split-screen menu for choosing packages to install (or remove). The top part of the screen is a relatively narrow window into the list of Debian's 18200 packages; the bottom part of the screen contains description of the package or group of packages which are highlighted above. One can specify which packages should be operated on by highlighting a package name or the label for a group of packages. After that, you can select packages: to be installed: This is accomplished by pressing the `+' key. to be deleted: Packages can be deleted two ways: * removed: this removes most of the files associated with the package, but preserves the files listed as configuration files (see Section 7.5, `What is a Debian conffile?') and package configuration information. This is done by pressing the `-' key. * purged: this removes _every_ file that is part of the package. This is done by pressing the `_' key. Note that it's not possible to remove "All Packages". If you try that, your system will instead be reduced to the initial installed base packages. to be put "on hold" This is done by pressing `=', and it effectively tells `dselect' not to upgrade a package even if the version currently installed on your system is not as recent as the version that is available in the Debian repository you are using (this was specified when you set the _Access Method_, and acquired when you used _Update_). Just like you can put a package on hold, you can reverse such setting by pressing `:'. That tells `dselect' that the package(s) may be upgraded if a newer version is available. This is the default setting. You can select a different order in which the packages are presented, by using the `o' key to cycle between various options for sorting the packages. The default order is to present packages by Priority; within each priority, packages are presented in order of the directory (a.k.a. section) of the archive in which they are stored. Given this sort order, some packages in section A (say) may be presented first, followed by some packages in section B, followed by more packages (of lower priority) in section A. You can also expand meanings of the labels at the top of the screen, by using the `v' (verbose) key. This action pushes much of the text that formerly fit onto the display off to the right. To see it, press the right arrow; to scroll back to the left, press the left arrow. If you select a package for installation or removal, e.g., `foo.deb', and that package depends on (or recommends) another package, e.g., `blurf.deb', then `dselect' will place the you in a sub-screen of the main selection screen. There you can choose among the related packages, accepting the suggested actions (to install or not), or rejecting them. To do the latter, press Shift-D; to return to the former, press Shift-U. In any case, you can save your selections and return to the main selection screen by pressing Shift-Q. * Users returning to the main menu can then select the "Install" menu item to unpack and configure the selected packages. Alternatively, users wishing to remove files can choose the "Remove" menu item. At any point, users can choose "Quit" to exit dselect; users' selections are preserved by `dselect'. 8.1.6.2. dpkg-deb ----------------- This program manipulates Debian archive(`.deb') files. Some common uses are: * Find out all the options: `dpkg-deb --help'. * Determine what files are contained in a Debian archive file: `dpkg-deb --contents foo_VVV-RRR.deb') * Extract the files contained in a named Debian archive into a user specified directory: `dpkg-deb --extract foo_VVV-RRR.deb tmp' extracts each of the files in `foo_VVV-RRR.deb' into the directory `tmp/'. This is convenient for examining the contents of a package in a localized directory, without installing the package into the root file system. * Extract the control information files from a package: `dpkg-deb --control foo_VVV-RRR.deb tmp'. Note that any packages that were merely unpacked using `dpkg-deb --extract' will be incorrectly installed, you should use `dpkg --install' instead. More information is given in the manual page dpkg-deb(1). 8.1.6.3. dpkg-split ------------------- This program splits large package into smaller files (e.g., for writing onto a set of floppy disks), and can also be used to merge a set of split files back into a single file. It can only be used on a Debian system (i.e. a system containing the `dpkg' package), since it calls the program `dpkg-deb' to parse the debian package file into its component records. For example, to split a big .deb file into N parts, * Execute the command `dpkg-split --split foo.deb'. This will produce N files each of approximately 460 KBytes long in the current directory. * Copy those N files to floppy disks. * Copy the contents of the floppy disks onto the hard disk of your choice on the other machine. * Join those part-files together using `dpkg-split --join "foo*"'. 8.2. Debian claims to be able to update a running program; how is this accomplished? ---------------------------------------------------------------------------- The kernel (file system) in Debian GNU/Linux systems supports replacing files even while they're being used. We also provide a program called `start-stop-daemon' which is used to start daemons at boot time or to stop daemons when the runlevel is changed (e.g., from multi-user to single-user or to halt). The same program is used by installation scripts when a new package containing a daemon is installed, to stop running daemons, and restart them as necessary. 8.3. How can I tell what packages are already installed on a Debian system? --------------------------------------------------------------------------- To learn the status of all the packages installed on a Debian system, execute the command dpkg --list This prints out a one-line summary for each package, giving a 2-letter status symbol (explained in the header), the package name, the version which is _installed_, and a brief description. To learn the status of packages whose names match the string any pattern beginning with "foo" by executing the command: dpkg --list 'foo*' To get a more verbose report for a particular package, execute the command: dpkg --status packagename 8.4. How to display the files of a package installed? ----------------------------------------------------- To list all the files provided by the installed package `foo' execute the command dpkg --listfiles foo Note that the files created by the installation scripts aren't displayed. 8.5. How can I find out what package produced a particular file? ---------------------------------------------------------------- To identify the package that produced the file named `foo' execute either: * `dpkg --search filename' This searches for `filename' in installed packages. (This is (currently) equivalent to searching all of the files having the file extension of `.list' in the directory `/var/lib/dpkg/info/', and adjusting the output to print the names of all the packages containing it, and diversions.) A faster alternative to this is the `dlocate' tool. dlocate -S filename * `zgrep foo Contents-ARCH.gz' This searches for files which contain the substring `foo' in their full path names. The files `Contents-ARCH.gz' (where ARCH represents the wanted architecture) reside in the major package directories (main, non-free, contrib) at a Debian FTP site (i.e. under `/debian/dists/etch'). A `Contents' file refers only to the packages in the subdirectory tree where it resides. Therefore, a user might have to search more than one `Contents' files to find the package containing the file `foo'. This method has the advantage over `dpkg --search' in that it will find files in packages that are not currently installed on your system. * `apt-file search ' If you install the `apt-file', similar to the above, it searches files which contain the substring or regular expression `foo' in their full path names. The advantage over the sample above is that there is no need to retrieve the `Contents-ARCH.gz' files as it will do this automatically for all the sources defined in `/etc/apt/sources.list' when you run (as root) `apt-file update'. 8.6. Why doesn't get `foo-data' removed when I uninstall `foo'? How do I make sure old unused library-packages get purged? ---------------------------------------------------------------------------- Some packages are split in program (`foo') and data (`foo-data') (or in `foo' and `foo-doc'). This is true for many games, multimedia applications and dictionaries in Debian and has been introduced since some users might want to access the raw data without installing the program or because the program can be run without the data itself, making it optional. Similar situations occur when dealing with libraries: generally these get installed since packages containing applications depend on them. When the application-package is purged, the library-package might stay on the system. Or: when the application-package no longer depends upon e.g. libdb4.2, but upon libdb4.3, the libdb4.2 package might stay when the application-package is upgraded. In these cases, `foo-data' doesn't depend on `foo', so when you remove the `foo' package it will not get automatically removed by most package management tools. The same holds true for the library packages. This is necessary to avoid circular dependencies. If you use `aptitude' (see Section 8.1.3, `aptitude') as your package management tool it will, however, track automatically installed packages and remove them when no packages remain that need them in your system. ------------------------------------------------------------------------------- 9. Keeping your Debian system up-to-date ---------------------------------------- A Debian goal is to provide a consistent upgrade path and a secure upgrade process. We always do our best to make upgrading to new releases a smooth procedure. In case there's some important note to add to the upgrade process, the packages will alert the user, and often provide a solution to a possible problem. You should also read the Release Notes document that describes the details of specific upgrades. It is shipped on all Debian CDs and available on the WWW at http://www.debian.org/releases/stable/releasenotes. 9.1. How can I keep my Debian system current? --------------------------------------------- One could simply execute an anonymous ftp call to a Debian archive, then peruse the directories until one finds the desired file, and then fetch it, and finally install it using `dpkg'. Note that `dpkg' will install upgrade files in place, even on a running system. Sometimes, a revised package will require the installation of a newly revised version of another package, in which case the installation will fail until/unless the other package is installed. Many people find this approach much too time-consuming, since Debian evolves so quickly -- typically, a dozen or more new packages are uploaded every week. This number is larger just before a new major release. To deal with this avalanche, many people prefer to use a more automated method. Several different packages are available for this purpose: 9.1.1. aptitude --------------- APT is an advanced interface to the Debian packaging system. It features complete installation ordering, multiple source capability and several other unique features, see the User's Guide in `/usr/share/doc/apt-doc/guide.html/index.html' (you will have to install the `apt-doc' package). `aptitude' is the recommended package manager for Debian GNU/Linux systems. It is a text-based interface to APT using the curses library, and can be used to perform management tasks in a fast and easy way. Before you can use `aptitude', you'll have to edit the `/etc/apt/sources.list' file to set it up. If you wish to upgrade to the latest stable version of Debian, you'll probably want to use a source like this one: http://ftp.us.debian.org/debian stable main contrib non-free You can replace ftp.us.debian.org with the name of a faster Debian mirror near you. See the mirror list at http://www.debian.org/mirror/list for more information. More details on this can be found in the sources.list(8) manual page. To update your system, run aptitude update followed by aptitude dist-upgrade Answer any questions that might come up, and your system will be upgraded. See also Section 8.1.3, `aptitude'. 9.1.2. apt-get, dselect and apt-cdrom ------------------------------------- `apt-get' is an APT-based command-line tool for handling packages, and the APT dselect method is an interface to APT through `dselect'. Both of these provide a simple, safe way to install and upgrade packages. To use `apt-get', install the `apt' package, and edit the `/etc/apt/sources.list' file to set it up, just as for Section 9.1.1, `aptitude'. Then run apt-get update followed by apt-get dist-upgrade Answer any questions that might come up, and your system will be upgraded. See also the apt-get(8) manual page, as well as Section 8.1.2, `APT'. To use APT with `dselect', choose the APT access method in dselect's method selection screen (option 0) and then specify the sources that should be used. The configuration file is `/etc/apt/sources.list'. See also Section 8.1.6.1, `dselect'. If you want to use CDs to install packages, you can use `apt-cdrom'. For details, please see the Release Notes, section "Setting up for an upgrade from a local mirror". Please note that when you get and install the packages, you'll still have them kept in your /var directory hierarchy. To keep your partition from overflowing, remember to delete extra files using `apt-get clean' and `apt-get autoclean', or to move them someplace else (hint: use `apt-move'). 9.1.3. aptitude --------------- `aptitude' is a text-based interface to the Debian package system. It allows the user to view the list of packages and to perform package management tasks such as installing, upgrading, and removing packages (see Section 8.1.3, `aptitude'). Actions may be performed from a visual interface or from the command-line. In command line, the actions are similar to that of APT, so to upgrade your system run aptitude update followed by aptitude dist-upgrade To upgrade from a preview release, `aptitude' is the tool recommended. Read the Release Notes at http://www.debian.org/releases/stable/releasenotes. For details, see the manual page aptitude(8), and the file `/usr/share/aptitude/README' 9.1.4. mirror ------------- This Perl script, and its (optional) manager program called `mirror-master', can be used to fetch user-specified parts of a directory tree from a specified host _via_ anonymous FTP. `mirror' is particularly useful for downloading large volumes of software. After the first time files have been downloaded from a site, a file called `.mirrorinfo' is stored on the local host. Changes to the remote file system are tracked automatically by `mirror', which compares this file to a similar file on the remote system and downloads only changed files. The `mirror' program is generally useful for updating local copies of remote directory trees. The files fetched need not be Debian files. (Since `mirror' is a Perl script, it can also run on non-Unix systems.) Though the `mirror' program provides mechanisms for excluding files names of which match user-specified strings, this program is most useful when the objective is to download whole directory trees, rather than selected packages. 9.1.5. dpkg-mountable --------------------- dpkg-mountable adds an access method called `mountable' to dselect's list, which allows you to install from any file system specified in /etc/fstab. For example, the archive could be a normal hard disk partition or an NFS server, which it will automatically mount and umount for you if necessary. It also has some extra features not found in the standard dselect methods, such as provision for a local file tree (either parallel to the main distribution or totally separate), and only getting packages which are required, rather than the time-consuming recursive directory scan, as well as logging of all dpkg actions in the install method. 9.2. Must I go into single user mode in order to upgrade a package? ------------------------------------------------------------------- No. Packages can be upgraded in place, even in running systems. Debian has a `start-stop-daemon' program that is invoked to stop, then restart running process if necessary during a package upgrade. 9.3. Do I have to keep all those .deb archive files on my disk? --------------------------------------------------------------- No. If you have downloaded the files to your disk then after you have installed the packages, you can remove them from your system, e.g. by running `aptitude clean'. 9.4. How can I keep a log of the packages I added to the system? I'd like to know when which package upgrades and removals have occured! ---------------------------------------------------------------------------- Passing the `--log'-option to `dpkg' makes `dpkg' log status change updates and actions. It logs both the `dpkg'-invokation (e.g. 2005-12-30 18:10:33 install hello 1.3.18 2.1.1-4 ) and the results (e.g. 2005-12-30 18:10:35 status installed hello 2.1.1-4 ) If you'd like to log all your `dpkg' invokations (even those done using frontends like `aptitude'), you could add log /var/log/dpkg.log to your `/etc/dpkg/dpkg.cfg'. Be sure the created logfile gets rotated periodically. If you're using `logrotate', this can be achieved by creating a file `/etc/logrotate.d/dpkg' with contents /var/log/dpkg { missingok notifempty } More details on `dpkg' logging can be found in the dpkg(1) manual page. `aptitude' logs the package installations, removals, and upgrades that it intends to perform to `/var/log/aptitude'. Note that the _results_ of those actions are not recorded in this file! Another way to record your actions is to run your package management session within the script(1) program. 9.5. Can I automatically update the system? ------------------------------------------- Yes. You can use `cron-apt', this tool updates the system at regular interval by using a cron job. By default it just updates the package list and download new packages without installing. Note: Automatic upgrade of packages is _NOT_ recommended in _testing_ or _unstable_ systems as this might bring unexpected behaviour and remove packages without notice. 9.6. I have several machines how can I download the updates only one time? -------------------------------------------------------------------------- If you have more than one Debian machine on your network, it is useful to use `apt-proxy' to keep all of your Debian systems up-to-date. `apt-proxy' reduces the bandwidth requirements of Debian mirrors by restricting the frequency of Packages, Releases and Sources file updates from the back end and only doing a single fetch for any file, independently of the actual request it from the proxy. `apt-proxy' automatically builds a Debian HTTP mirror based on requests which pass through the proxy. For more details, see the apt-proxy homepage at http://apt-proxy.sourceforge.net/ Of course, you can get the same benefit if you are already using a standard caching proxy and all your systems are configured to use it. ------------------------------------------------------------------------------- 10. Debian and the kernel ------------------------- 10.1. Can I install and compile a kernel without some Debian-specific tweaking? ---------------------------------------------------------------------------- Yes. There's only one common catch: the Debian C libraries are built with the most recent _stable_ releases of the _kernel_ headers. If you happen to need to compile a program with kernel headers newer than the ones from the stable branch, then you should either upgrade the package containing the headers (`libc6-dev'), or use the new headers from an unpacked tree of the newer kernel. That is, if the kernel sources are in `/usr/src/linux', then you should add `-I/usr/src/linux/include/' to your command line when compiling. 10.2. What tools does Debian provide to build custom kernels? ------------------------------------------------------------- Users who wish to (or must) build a custom kernel are encouraged to download the package `kernel-package'. This package contains the script to build the kernel package, and provides the capability to create a Debian `linux-image-' package just by running the command make-kpkg --initrd kernel_image in the top-level kernel source directory. Help is available by executing the command make-kpkg --help and through the manual page make-kpkg(1). Users must separately download the source code for the most recent kernel (or the kernel of their choice) from their favorite Linux archive site, unless a `linux-source-' package is available (where stands for the kernel version). Detailed instructions for using the `kernel-package' package are given in the file `/usr/share/doc/kernel-package/README.gz'. 10.3. How can I make a custom boot floppy? ------------------------------------------ This task is greatly aided by the Debian package `boot-floppies', normally found in the `admin' section of the Debian FTP archive. Shell scripts in this package produce boot floppies in the `SYSLINUX' format. These are `MS-DOS' formatted floppies whose master boot records have been altered so that they boot Linux directly (or whatever other operating system has been defined in the `syslinux.cfg' file on the floppy). Other scripts in this package produce emergency root disks and can even reproduce the base disks. You will find more information about this in the `/usr/share/doc/boot-floppies/README' file after installing the `boot-floppies' package. 10.4. What special provisions does Debian provide to deal with modules? ----------------------------------------------------------------------- Debian's `modconf' package provides a shell script (`/usr/sbin/modconf') which can be used to customize the configuration of modules. This script presents a menu-based interface, prompting the user for particulars on the loadable device drivers in his system. The responses are used to customize the file `/etc/modules.conf' (which lists aliases, and other arguments that must be used in conjunction with various modules) through files in `/etc/modutils/', and `/etc/modules' (which lists the modules that must be loaded at boot time). Like the (new) `Configure.help' files that are now available to support the construction of custom kernels, the `modconf' package comes with a series of help files (in `/usr/lib/modules_help/') which provide detailed information on appropriate arguments for each of the modules. 10.5. Can I safely de-install an old kernel package, and if so, how? -------------------------------------------------------------------- Yes. The `linux-image-.prerm' script checks to see whether the kernel you are currently running is the same as the kernel you are trying to de-install. Therefore you can remove unwanted kernel image packages using this command: dpkg --purge linux-image- (replace with your kernel version and revision number, of course) ------------------------------------------------------------------------------- 11. Customizing your installation of Debian GNU/Linux ----------------------------------------------------- 11.1. How can I ensure that all programs use the same paper size? ----------------------------------------------------------------- Install the `libpaper1' package, and it will ask you for a system-wide default paper size. This setting will be kept in the file `/etc/papersize'. Users can override the paper size setting using the `PAPERSIZE' environment variable. For details, see the manual page papersize(5). 11.2. How can I provide access to hardware peripherals, without compromising security? ---------------------------------------------------------------------------- Many device files in the `/dev' directory belong to some predefined groups. For example, `/dev/fd0' belongs to the `floppy' group, and `/dev/dsp' belongs to the `audio' group. If you want a certain user to have access to one of these devices, just add the user to the group the device belongs to, i.e. do: adduser user group This way you won't have to change the file permissions on the device. If you do this from within a user's shell or a GUI environment you have to logout and login again to become an effective member of that group. To check which groups you belong to run `groups'. Notice that, since the introduction of `udev' if you change the permissions of a hardware peripheral they might be be adjusted for some devices when the system starts, if this happens to the hardware peripherals you are instered in you will have to adjust the rules at `/etc/udev'. 11.3. How do I load a console font on startup the Debian way? ------------------------------------------------------------- The `kbd' and `console-tools' packages support this, edit `/etc/kbd/config' or `/etc/console-tools/config' files. 11.4. How can I configure an X11 program's application defaults? ---------------------------------------------------------------- Debian's X programs will install their application resource data in the `/etc/X11/app-defaults/' directory. If you want to customize X applications globally, put your customizations in those files. They are marked as configuration files, so their contents will be preserved during upgrades. 11.5. Every distribution seems to have a different boot-up method. Tell me about Debian's. ---------------------------------------------------------------------------- Like all Unices, Debian boots up by executing the program `init'. The configuration file for `init' (which is `/etc/inittab') specifies that the first script to be executed should be `/etc/init.d/rcS'. This script runs all of the scripts in `/etc/rcS.d/' by sourcing or forking subprocess depending on their file extension to perform initialization such as to check and to mount file systems, to load modules, to start the network services, to set the clock, and to perform other initialization. Then, for compatibility, it runs the files (except those with a `.'in the filename) in `/etc/rc.boot/' too. Any scripts in the latter directory are usually reserved for system administrator use, and using them in packages is deprecated. After completing the boot process, `init' executes all start scripts in a directory specified by the default runlevel (this runlevel is given by the entry for `id' in `/etc/inittab'). Like most System V compatible Unices, Linux has 7 runlevels: * 0 (halt the system), * 1 (single-user mode), * 2 through 5 (various multi-user modes), and * 6 (reboot the system). Debian systems come with id=2, which indicates that the default runlevel will be '2' when the multi-user state is entered, and the scripts in `/etc/rc2.d/' will be run. In fact, the scripts in any of the directories, `/etc/rcN.d/' are just symbolic links back to scripts in `/etc/init.d/'. However, the _names_ of the files in each of the `/etc/rcN.d/' directories are selected to indicate the _way_ the scripts in `/etc/init.d/' will be run. Specifically, before entering any runlevel, all the scripts beginning with 'K' are run; these scripts kill services. Then all the scripts beginning with 'S' are run; these scripts start services. The two-digit number following the 'K' or 'S' indicates the order in which the script is run. Lower numbered scripts are executed first. This approach works because the scripts in `/etc/init.d/' all take an argument which can be either `start', `stop', `reload', `restart' or `force-reload' and will then do the task indicated by the argument. These scripts can be used even after a system has been booted, to control various processes. For example, with the argument `reload' the command /etc/init.d/sendmail reload sends the sendmail daemon a signal to reread its configuration file. (BTW, Debian supplies `invoke-rc.d' as a wrapper for invoking the scripts in `/etc/init.d/'.) 11.6. It looks as if Debian does not use `rc.local' to customize the boot process; what facilities are provided? ---------------------------------------------------------------------------- Suppose a system needs to execute script `foo' on start-up, or on entry to a particular (System V) runlevel. Then the system administrator should: * Enter the script `foo' into the directory `/etc/init.d/'. * Run the Debian command `update-rc.d' with appropriate arguments, to specify which runlevels should start the service, and which runlevels should stop the service. * Consider rebooting the system to check that the service starts correctly (assuming that you've asked for it to be started in the default runlevel). Otherwise, manually start it by running ``/etc/init.d/foo start''. One might, for example, cause the script `foo' to execute at boot-up, by putting it in `/etc/init.d/' and running `update-rc.d foo defaults 19'. The argument ``defaults'' refers to the default runlevels, which means (at least in absence of any LSB comment block to the contrary) to start the service in runlevels 2 through 5, and to stop the service in runlevels 0, 1 and 6. (Any LSB Default-Start and Default-Stop directives in `foo' take precedence when using the sysv-rc version of update-rc.d, but are ignored by the current (v0.8.10) file-rc version of update-rc.d.) The argument ``19'' ensures that `foo' is called after all scripts whose number is less than 19 have completed, and before all scripts whose number is 20 or greater. 11.7. How does the package management system deal with packages that contain configuration files for other packages? ---------------------------------------------------------------------------- Some users wish to create, for example, a new server by installing a group of Debian packages and a locally generated package consisting of configuration files. This is not generally a good idea, because `dpkg' will not know about those configuration files if they are in a different package, and may write conflicting configurations when one of the initial "group" of packages is upgraded. Instead, create a local package that modifies the configuration files of the "group" of Debian packages of interest. Then `dpkg' and the rest of the package management system will see that the files have been modified by the local "sysadmin" and will not try to overwrite them when those packages are upgraded. 11.8. How do I override a file installed by a package, so that a different version can be used instead? ---------------------------------------------------------------------------- Suppose a sysadmin or local user wishes to use a program "login-local" rather than the program "login" provided by the Debian `login' package. Do _not_: * Overwrite `/bin/login' with `login-local'. The package management system will not know about this change, and will simply overwrite your custom `/bin/login' whenever `login' (or any package that provides `/bin/login') is installed or updated. Rather, do * Execute: dpkg-divert --divert /bin/login.debian /bin/login in order to cause all future installations of the Debian `login' package to write the file `/bin/login' to `/bin/login.debian' instead. * Then execute: cp login-local /bin/login to move your own locally-built program into place. Run `dpkg-divert --list' to see which diversions are currently active on your system. Details are given in the manual page dpkg-divert(8). 11.9. How can I have my locally-built package included in the list of available packages that the package management system knows about? ---------------------------------------------------------------------------- Execute the command: dpkg-scanpackages BIN_DIR OVERRIDE_FILE [PATHPREFIX] > my_Packages where: * BIN-DIR is a directory where Debian archive files (which usually have an extension of ".deb") are stored. * OVERRIDE_FILE is a file that is edited by the distribution maintainers and is usually stored on a Debian FTP archive at `indices/override.main.gz' for the Debian packages in the "main" distribution. You can ignore this for local packages. * PATHPREFIX is an _optional_ string that can be prepended to the `my_Packages' file being produced. Once you have built the file `my_Packages', tell the package management system about it by using the command: dpkg --merge-avail my_Packages If you are using APT, you can add the local repository to your sources.list(5) file, too. 11.10. Some users like mawk, others like gawk; some like vim, others like elvis; some like trn, others like tin; how does Debian support diversity? ---------------------------------------------------------------------------- There are several cases where two packages provide two different versions of a program, both of which provide the same core functionality. Users might prefer one over another out of habit, or because the user interface of one package is somehow more pleasing than the interface of another. Other users on the same system might make a different choice. Debian uses a "virtual" package system to allow system administrators to choose (or let users choose) their favorite tools when there are two or more that provide the same basic functionality, yet satisfy package dependency requirements without specifying a particular package. For example, there might exist two different versions of newsreaders on a system. The news server package might 'recommend' that there exist _some_ news reader on the system, but the choice of `tin' or `trn' is left up to the individual user. This is satisfied by having both the `tin' and `trn' packages provide the virtual package `news-reader'. _Which_ program is invoked is determined by a link pointing from a file with the virtual package name `/etc/alternatives/news-reader' to the selected file, e.g., `/usr/bin/trn'. A single link is insufficient to support full use of an alternate program; normally, manual pages, and possibly other supporting files must be selected as well. The Perl script `update-alternatives' provides a way of ensuring that all the files associated with a specified package are selected as a system default. For example, to check what executables provide `x-window-manager', run: update-alternatives --display x-window-manager If you want to change it, run: update-alternatives --config x-window-manager And follow the instructions on the screen (basically, press the number next to the entry you'd like better). If a package doesn't register itself as a window manager for some reason (file a bug if it's in error), or if you use a window manager from /usr/local directory, the selections on screen won't contain your preferred entry. You can update the link through command line options, like this: update-alternatives --install /usr/bin/x-window-manager \ x-window-manager /usr/local/bin/wmaker-cvs 50 The first argument to `--install' option is the symlink that points to /etc/alternatives/NAME, where NAME is the second argument. The third argument is the program to which /etc/alternatives/NAME should point to, and the fourth argument is the priority (larger value means the alternative will more probably get picked automatically). To remove an alternative you added, simply run: update-alternatives --remove x-window-manager /usr/local/bin/wmaker-cvs ------------------------------------------------------------------------------- 12. Getting support for Debian GNU/Linux ---------------------------------------- 12.1. What other documentation exists on and for a Debian system? ----------------------------------------------------------------- * Installation instructions for the current release: see http://www.debian.org/releases/stable/installmanual. * The Debian GNU/Linux reference covers many aspects of system administration through shell-command examples. Basic tutorials, tips, and other information are provided for many different topics ranging from system administration to programming. Get it from the `debian-reference' package, or at http://www.debian.org/doc/user-manuals#quick-reference. * The Debian Policy manual documents the policy requirements for the distribution, i.e. the structure and contents of the Debian archive, several design issues of the operating system etc. It also includes the technical requirements that each package must satisfy to be included in the distribution, and documents the basic technical aspects of Debian binary and source packages. Get it from the `debian-policy' package, or at http://www.debian.org/doc/devel-manuals#policy. * Documentation developed by the Debian Documentation Project. It is available at http://www.debian.org/doc/ and includes user guides, administration guides and security guides for the Debian GNU/Linux operating system. * Documentation on installed Debian packages: Most packages have files that are unpacked into `/usr/share/doc/PACKAGE'. * Documentation on the Linux project: The Debian package `doc-linux' installs all of the most recent versions of the HOWTOs and mini-HOWTOs from the Linux Documentation Project (http://www.tldp.org/). * Unix-style `man' pages: Most commands have manual pages written in the style of the original Unix 'man' files. For instance, to see the manual page for the command `ls', execute `man ls'. Execute `man man' for more information on finding and viewing manual pages. New Debian users should note that the 'man' pages of many general system commands are not available until they install these packages: * `man-db', which contains the `man' program itself, and other programs for manipulating the manual pages. * `manpages', which contains the system manual pages. (see Section 5.9, `How does Debian support non-English languages?'). * GNU-style `info' pages: User documentation for many commands, particularly GNU tools, is available not in `man' pages, but in `info' files which can be read by the GNU tool `info', by running `M-x info' within GNU Emacs, or with some other Info page viewer. Its main advantage over the original `man' pages are that it is a hypertext system. It does _not_ require the WWW, however; `info' can be run from a plain text console. It was designed by Richard Stallman and preceded the WWW. Note that you may access a lot of documentation on your system by using a WWW browser, through `dwww', `dhelp' or `doccentral' commands, found in respective packages, or by using `yelp'. 12.2. Are there any on-line resources for discussing Debian? ------------------------------------------------------------ Yes. In fact, the main method of support Debian provides to our users is by the way of e-mail. We'll give some details on that, and mention some other useful resources. Even more resources are listed at the Debian Support webpage (http://www.debian.org/support). 12.2.1. Mailing lists --------------------- There are a lot of Debian-related mailing lists (http://www.debian.org/MailingLists/). On a system with the `doc-debian' package installed there is a complete list of mailing lists in `/usr/share/doc/debian/mailing-lists.txt'. Debian mailing lists are named following the pattern debian-. Examples are debian-announce, debian-user, debian-news. To subscribe to any list debian-, send mail to debian--request@lists.debian.org with the word "subscribe" in the Subject: header. Be sure to remember to add _-request_ to the e-mail address when using this method to subscribe or unsubscribe. Otherwise your e-mail will go to the list itself, which could be embarrassing or annoying, depending on your point of view. You can subscribe to mailing lists using the WWW form (http://www.debian.org/MailingLists/subscribe). You can also un-subscribe using a WWW form (http://www.debian.org/MailingLists/unsubscribe). The list manager's e-mail address is , in case you have any trouble. The mailing lists are public forums. All e-mails sent to the lists are also copied to the public archive, for anybody (even non-subscribers) to browse or search. Please make sure you never send any confidential or unlicensed material to the lists. This includes things like e-mail addresses. Of particular note is the fact that spammers have been known to abuse e-mail addresses posted to our mailing lists. See the Mailing Lists Privacy policy (http://www.debian.org/MailingLists/index.en.html#disclaimer) for more information. Archives of the Debian mailing lists are available via WWW at http://lists.debian.org/. 12.2.1.1. What is the code of conduct for the mailing lists? ------------------------------------------------------------ When using the Debian mailing lists, please follow these rules: * Do not send spam. See the Debian mailing list advertising policy (http://www.debian.org/MailingLists/#ads). * Do not flame; it is not polite. The people developing Debian are all volunteers, donating their time, energy and money in an attempt to bring the Debian project together. * Do not use foul language; besides, some people receive the lists via packet radio, where swearing is illegal. * Make sure that you are using the proper list. _Never_ post your (un)subscription requests to the mailing list itself[1] * See section Section 12.5, `How do I report a bug in Debian?' for notes on reporting bugs. [1] Use the debian--REQUEST@lists.debian.org address for that. 12.2.2. Web forums ------------------ debianHELP (http://debianhelp.org/) and Debian User Forums (http://forums.debian.net/) are web forums on which you can submit questions about Debian and have them answered by other users. (These are not officially part of the Debian project.) 12.2.3. Wiki ------------ Solutions to common problems, howto's, guides, tips and other documentation can be found at the constantly changing Debian Wiki (http://wiki.debian.org/). 12.2.4. Maintainers ------------------- Users can address questions to individual package maintainers using e-mail. To reach a maintainer of a package called xyz, send e-mail to _xyz@packages.debian.org_. 12.2.5. Usenet newsgroups ------------------------- Users should post non-Debian-specific questions to one of the Linux USENET groups, which are named comp.os.linux.* or linux.*. There are several lists of Linux Usenet newsgroups and other related resources on the WWW, e.g. on the Linux Online (http://www.linux.org/docs/usenet.html) and LinuxJournal (http://www.linuxjournal.com/helpdesk.php) sites. 12.3. Is there a quick way to search for information on Debian GNU/Linux? ------------------------------------------------------------------------- There is a variety of search engines that serve documentation related to Debian: * Debian WWW search site (http://search.debian.org/). * Google Groups (http://groups.google.com/): a search engine for newsgroups. For example, to find out what experiences people have had with finding drivers for Promise controllers under Debian, try searching on the phrase `Promise Linux driver'. This will show you all the postings that contain these strings, i.e. those where people discussed these topics. If you add `Debian' to those search strings, you'll also get the postings specifically related to Debian. * Any of the common web spidering engines, such as AltaVista (http://www.altavista.com/) or Google (http://www.google.com/), as long as you use the right search terms. For example, searching on the string "cgi-perl" gives a more detailed explanation of this package than the brief description field in its control file. 12.4. Are there logs of known bugs? ----------------------------------- Reports on unsolved (and closed) issues are publicly available: Debian promissed to do so by stating "We will not hide problems" in the Debian Social Contract (http://www.debian.org/social_contract). The Debian GNU/Linux distribution has a bug tracking system (BTS) which files details of bugs reported by users and developers. Each bug is given a number, and is kept on file. Once it has been dealt with, it is marked as such. Copies of this information are available at http://www.debian.org/Bugs/. A mail server provides access to the bug tracking system database via e-mail. In order to get the instructions, send an e-mail to request@bugs.debian.org with "help" in the body. 12.5. How do I report a bug in Debian? -------------------------------------- If you have found a bug in Debian, please read the instructions for reporting a bug in Debian. These instructions can be obtained in one of several ways: * From the WWW. A copy of the instructions is shown at http://www.debian.org/Bugs/Reporting. * On any Debian system with the `doc-debian' package installed. The instructions are in the file `/usr/share/doc/debian/bug-reporting.txt'. * By anonymous FTP. Debian mirror sites contain the instructions in the file `doc/bug-reporting.txt'. You can use the package `reportbug' that will guide you through the reporting process and mail the message to the proper address, with some extra details about your system added automatically. It will also show you a list of bugs already reported to the package you are reporting against in case your bug has been reported previously, so that you can add additional information to the existing bug report. Expect to get an automatic acknowledgement of your bug report. It will also be automatically given a bug tracking number, entered into the bug log and forwarded to the debian-bugs-dist mailing list. ------------------------------------------------------------------------------- 13. Contributing to the Debian Project -------------------------------------- Donations (http://www.debian.org/donations) of time (to develop new packages, maintain existing packages, or provide user support), resources (to mirror the FTP and WWW archives), and money (to pay for new testbeds as well as hardware for the archives) can help the project. 13.1. How can I become a Debian software developer? --------------------------------------------------- The development of Debian is open to all, and new users with the right skills and/or the willingness to learn are needed to maintain existing packages which have been "orphaned" by their previous maintainers, to develop new packages, and to provide user support. The description of becoming a Debian developer can be found at the New Maintainer's Corner (http://www.debian.org/devel/join/newmaint) at the Debian web site. 13.2. How can I contribute resources to the Debian project? ----------------------------------------------------------- Since the project aims to make a substantial body of software rapidly and easily accessible throughout the globe, mirrors are urgently needed. It is desirable but not absolutely necessary to mirror all of the archive. Please visit the Debian mirror size (http://www.debian.org/mirror/size) page for information on the disk space requirements. Most of the mirroring is accomplished entirely automatically by scripts, without any interaction. However, the occasional glitch or system change occurs which requires human intervention. If you have a high-speed connection to the Internet, the resources to mirror all or part of the distribution, and are willing to take the time (or find someone) who can provide regular maintenance of the system, then please contact . 13.3. How can I contribute financially to the Debian project? ------------------------------------------------------------- One can make individual donations to one of two organizations that are critical to the development of the Debian project. 13.3.1. Software in the Public Interest --------------------------------------- Software in the Public Interest (SPI) is an IRS 501(c)(3) non-profit organization, formed when FSF withdrew their sponsorship of Debian. The purpose of the organization is to develop and distribute free software. Our goals are very much like those of FSF, and we encourage programmers to use the GNU General Public License on their programs. However, we have a slightly different focus in that we are building and distributing a Linux system that diverges in many technical details from the GNU system as originally planned by FSF. We still communicate with FSF, and we cooperate in sending them changes to GNU software and in asking our users to donate to FSF and the GNU project. SPI can be reached at: http://www.spi-inc.org/. 13.3.2. Free Software Foundation -------------------------------- At this time there is no formal connection between Debian and the Free Software Foundation. However, the Free Software Foundation is responsible for some of the most important software components in Debian, including the GNU C compiler, GNU Emacs, and much of the C run-time library that is used by all programs on the system. FSF pioneered much of what free software is today: they wrote the General Public License that is used on much of the Debian software, and they invented the "GNU" project to create an entirely free Unix system. Debian should be considered a descendent of the GNU system. FSF can be reached at: http://www.fsf.org/. ------------------------------------------------------------------------------- 14. Redistributing Debian GNU/Linux in a commercial product ----------------------------------------------------------- 14.1. Can I make and sell Debian CDs? ------------------------------------- Go ahead. You do not need permission to distribute anything we have _released_, so that you can master your CD as soon as the beta-test ends. You do not have to pay us anything. Of course, all CD manufacturers must honor the licenses of the programs in Debian. For example, many of the programs are licensed under the GPL, which requires you to distribute their source code. Also, we will publish a list of CD manufacturers who donate money, software, and time to the Debian project, and we will encourage users to buy from manufacturers who donate, so it is good advertising to make donations. 14.2. Can Debian be packaged with non-free software? ---------------------------------------------------- Yes. While all the main components of Debian are free software, we provide a non-free directory for programs that are not freely redistributable. CD manufacturers _may_ be able to distribute the programs we have placed in that directory, depending on the license terms or their private arrangements with the authors of those software packages. CD manufacturers can also distribute the non-free software they get from other sources on the same CD. This is nothing new: free and commercial software are distributed on the same CD by many manufacturers now. Of course we still encourage software authors to release the programs they write as free software. 14.3. I am making a special Linux distribution for a "vertical market". Can I use Debian GNU/Linux for the guts of a Linux system and add my own applications on top of it? ---------------------------------------------------------------------------- Yes. Debian-derived distributions are being created both in close cooperation with the Debian project itself and by external parties. One can use the Custom Debian Distributions (http://cdd.alioth.debian.org/) framework to work together with Debian; Skolelinux (http://www.skolelinux.org/) is one such project. There are several other Debian-derived distributions already on the market, such as Progeny Debian, Linspire, Knoppix and Ubuntu, that are targeted at a different kind of audience than the original Debian GNU/Linux is, but use most of our components in their product. Debian also provides a mechanism to allow developers and system administrators to install local versions of selected files in such a way that they will not be overwritten when other packages are upgraded. This is discussed further in the question on Section 11.8, `How do I override a file installed by a package, so that a different version can be used instead?'. 14.4. Can I put my commercial program in a Debian "package" so that it installs effortlessly on any Debian system? ---------------------------------------------------------------------------- Go right ahead. The package tool is free software; the packages may or may not be free software, it can install them all. ------------------------------------------------------------------------------- 15. Changes expected in the next major release of Debian -------------------------------------------------------- 15.1. Extended support for non-English users -------------------------------------------- Debian already has very good support for non-English users, see Section 5.9, `How does Debian support non-English languages?'. We hope to find people who will provide support for even more languages, and translate. Some programs already support internationalization, so we need message catalogs translators. Many programs still remain to be properly internationalized. The GNU Translation Project ftp://ftp.gnu.org/pub/gnu/ABOUT-NLS works on internationalizing the GNU programs. Specifically for Debian lenny, we're working on things like the following: * I18n support in all debconf-using packages: Packages using the Debian configuration management must allow for translation of all messages displayed to the user during package configuration. * I18n support for package descriptions: Update package management frontends to use the translated descriptions of packages. * UTF-8 debian/changelog and debian/control. This way, e.g. names of people from asian countries can get typeset the right way in changelogs. 15.2. Faster booting: Dependency based boot sequence ---------------------------------------------------- Work is being done on converting the Debian boot sequence (http://wiki.debian.org/LSBInitScripts/DependencyBasedBoot) to use dynamic and dependency based ordering instead of hardcoded sequence numbers. Once that's finished, Debian systems will boot much faster. 15.3. Improvements in the Debian Installer ------------------------------------------ Lots of work has been done on the Debian Installer, resulting in major improvements. We'll mention just two of them here. Starting the installer from Microsoft Windows: It is now possible to start the installer directly from Microsoft Windows without the need to change BIOS settings. Upon insertion of a CD-ROM, DVD-ROM or USB stick, an autorun program will be started, offering a step-by-step process to start the Debian Installer. The debian-installer now includes experimental support for installing Debian on systems with Serial ATA RAID. 15.4. More architectures ------------------------ Complete Debian system on other architectures such as ARM EABI (http://wiki.debian.org/ArmEabiPort) (referred to as "armel") (next to the old "arm") will likely get supported with lenny. Support for SuperH (http://wiki.debian.org/SHPort) is expected soon. Notice that even though some architectures are dropped for a given the release there still might be a way to install and upgrade using the latest `sid'. 15.5. More kernels ------------------ In addition to Debian GNU/Hurd, Debian is being ported also to BSD kernels, namely to FreeBSD (http://www.debian.org/ports/kfreebsd-gnu/). This port runs on both AMD64 ("kfreebsd-amd64") and traditional Intel ("kfreebsd-i386"). ------------------------------------------------------------------------------- 16. General information about the FAQ ------------------------------------- 16.1. Authors ------------- The first edition of this FAQ was made and maintained by J.H.M. Dassen (Ray) and Chuck Stickelman. Authors of the rewritten Debian GNU/Linux FAQ are Susan G. Kleinmann and Sven Rudolph. After them, the FAQ was maintained by Santiago Vila and, later, by Josip Rodin. The current maintainer is Javier Fernandez-Sanguino. Parts of the information came from: * The Debian-1.1 release announcement, by Bruce Perens (http://www.perens.com/). * The Linux FAQ, by Ian Jackson (http://www.chiark.greenend.org.uk/~ijackson/). * Debian Mailing Lists Archives (http://lists.debian.org/), * the dpkg programmers' manual and the Debian Policy manual (see Section 12.1, `What other documentation exists on and for a Debian system?') * many developers, volunteers, and beta testers, and * the flaky memories of its authors. :-) * Kamaraju Kusumanchi's Choosing a Debian distribution FAQ (http://people.cornell.edu/pages/kk288/debian_choosing_distribution.html), who graciously made it GPL so I could include it as a new chapter (see Chapter 3, `Choosing a Debian distribution') The authors would like to thank all those who helped make this document possible. All warranties are disclaimed. All trademarks are property of their respective trademark owners. 16.2. Feedback -------------- Comments and additions to this document are always welcome. Please send e-mail to , or submit a wishlist bug report against the `debian-faq (http://bugs.debian.org/debian-faq)' package. 16.3. Availability ------------------ The latest version of this document can be viewed on the Debian WWW pages at http://www.debian.org/doc/FAQ/. It is also available for download in plain text, HTML, PostScript and PDF formats at http://www.debian.org/doc/user-manuals#faq. Also, there are several translations there. This document is available in the `debian-faq' package. Translations are available in `debian-faq-de', `debian-faq-fr' and other packages. The original SGML files used to create this document are also available in `debian-faq''s source package, or in SVN at: `svn://svn.debian.org/svn/ddp/manuals/trunk/debian-faq' and http://svn.debian.org/viewsvn/ddp/manuals/trunk/debian-faq/. 16.4. Document format --------------------- This document was written using the DebianDoc SGML DTD (rewritten from LinuxDoc SGML). DebianDoc SGML systems enables us to create files in a variety of formats from one source, e.g. this document can be viewed as HTML, plain text, TeX DVI, PostScript, PDF, or GNU info. Conversion utilities for DebianDoc SGML are available in Debian package `debiandoc-sgml'. ------------------------------------------------------------------------------- The Debian GNU/Linux FAQ Authors are listed at Debian FAQ Authors version 4.0.4+nmu1, 3 January 2010