Table of Contents
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This release drops official support for the HP PA-RISC ('hppa'), Alpha ('alpha') and ARM ('arm') architectures.
The following are the officially supported architectures for Debian GNU/Linux squeeze:
32-bit PC ('i386')
SPARC ('sparc')
PowerPC ('powerpc')
MIPS ('mips' (big-endian) and 'mipsel' (little-endian))
Intel Itanium ('ia64')
S/390 ('s390')
64-bit PC ('amd64')
ARM EABI ('armel')
In addition to the officially supported architectures, Debian GNU/Linux squeeze introduces the GNU/kFreeBSD ports ('kfreebsd-amd64' and 'kfreebsd-i386') as a technology preview. These ports are the first ones included in a Debian release which aren't based on the Linux kernel, but instead use the FreeBSD kernel with a GNU userland. Users of these versions however should be warned that the quality of these ports is still catching up with the outstanding high quality of our Linux ports, and that some advanced desktop features are not supported yet. However, the support of common server software is strong and extends the features of Linux-based Debian versions by the unique features known from the BSD world. This is the first time a Linux distribution has been extended to also allow use of a non-Linux kernel.
You can read more about port status, and port-specific information for your architecture at the Debian port web pages.
This new release of Debian again comes with a lot more software than its predecessor lenny; the distribution includes over 10352 new packages, for a total of over 29050 packages. Most of the software in the distribution has been updated: over 15436 software packages (this is 67% of all packages in lenny). Also, a significant number of packages (over 4238, 18% of the packages in lenny) have for various reasons been removed from the distribution. You will not see any updates for these packages and they will be marked as 'obsolete' in package management front-ends.
With this release, Debian GNU/Linux updates from X.Org 7.3 to X.Org 7.5.
Debian GNU/Linux again ships with several desktop applications and environments. Among others it now includes the desktop environments GNOME 2.30[1], KDE 4.4.5, Xfce 4.6.2, and LXDE 0.5.0. Productivity applications have also been upgraded, including the office suites OpenOffice.org 3.2.1 and KOffice 2.2.1 as well as GNUcash 2.2.9, GNUmeric 1.10.8 and Abiword 2.8.2.
Updates of other desktop applications include the upgrade to
Evolution 2.30.3
and Pidgin 2.7.3.
The Mozilla suite has
also been updated:
iceweasel
(version 3.5.13) is the unbranded
Firefox
web browser and
icedove
(version 3.0.7) is the unbranded
Thunderbird
mail client.
Among many others, this release also includes the following software updates:
The official Debian GNU/Linux distribution now ships on 4 to 5 binary
DVDs
or 28 to 32 binary CDs
(depending on the
architecture) and 4 source DVDs or 28 source
CDs. Additionally, there is a
multi-arch DVD, with a
subset of the release for the amd64 and
i386 architectures, along with the source code.
Debian GNU/Linux is also released as Blu-ray
images, also for
the amd64 and i386
architectures, along with the source code.
Debian still supports Linux Standard Base (LSB) version 3.2.
Some drivers included in the Linux kernel used to contain non-free firmware
blobs. Starting from squeeze this firmware has been moved to separate
packages in the non-free section of the archive, such as firmware-linux. If such packages are installed,
the firmware will be loaded automatically when required.
The preferred program for interactive package management from a terminal is
aptitude. For a non-interactive command line interface
for package management, it is recommended to use apt-get.
apt-get is also the preferred tool for upgrades
between major releases.
If you are still using dselect, you should switch to
aptitude as the official front-end
for package management.
For squeeze APT automatically installs recommended packages by default[2].
This can be changed by adding the following line in
/etc/apt/apt.conf:
APT::Install-Recommends "false";
An important improvement in the Debian GNU/Linux boot system is the introduction of dependency-based boot sequencing and parallel boot. This feature is enabled by default in new installs and it will be enabled for upgrades from lenny, if possible.
This feature is enabled through the use of insserv
by sysv-rc to order init.d scripts based on their declared
dependencies[3].
It has been possible after a sustained effort to adapt all the boot scripts
of packages provided in the distribution as well as the boot system itself.
With dependency-based boot sequencing it is also now possible to run the boot system scripts in parallel which can, under most circumstances, improve the speed of the boot process. This feature is enabled by default, in new systems and upgrades, whenever possible. To disable it specify
CONCURRENCY=none
in /etc/default/rcS.
For more information on this feature refer to the information available in
/usr/share/doc/insserv/README.Debian.
In this new release, the settings for the keyboard have been unified so that
both the console and the Xorg server use the same settings. The keyboard
settings are now defined in the /etc/default/keyboard
configuration file which overrides the keyboard defined in Xorg's
configuration file.
The console-setup package now
handles the keyboard for both environments as well as the font
configuration for the console. You can reconfigure the keyboard layout and
related settings by executing
dpkg-reconfigure keyboard-configuration
or by manually editing the /etc/default/keyboard
configuration file.
Graphics mode setting code for the most common desktop chipsets (from Intel, ATI/AMD and NVIDIA) has moved from the respective Xorg drivers to the Linux kernel. This provides a number of advantages, such as:
More reliable suspend and resume
Ability to use graphics devices without X
Faster VT switch
Native mode text console
More details are in Section 5.6, “Graphics stack changes” and in the Debian wiki.
This Debian release comes with several options for implementing
client-side authentication using LDAP.
Users of the libnss-ldap and
libpam-ldap packages should
consider upgrading to
libnss-ldapd and
libpam-ldapd.
These newer packages delegate the LDAP queries to a central unprivileged daemon (nslcd) that provides separation between the process using the LDAP information and the daemon performing LDAP queries. This simplifies handling of secured LDAP connections, LDAP authentication credentials, provides a simpler mechanism to perform connection fail-over and debugging and avoids loading LDAP and related libraries into most applications.
Upgrading to libnss-ldapd and
libpam-ldapd should be easy
as existing configuration information will be mostly reused.
Only for advanced configuration should any manual reconfiguration be
necessary.
These packages however currently lack support for nested groups and only support password change using the LDAP password modify EXOP operation.
All changes to the released stable distribution (and to oldstable)
go through an extended testing period before they are accepted
into the archives. Each such update of the stable (or oldstable)
release is called a point release. Preparation of point releases
is done through the proposed-updates mechanism.
Packages can enter proposed-updates in two
ways. Firstly, security-patched packages added to security.debian.org are
automatically added to proposed-updates as well.
Secondly, Debian GNU/Linux developers may upload new packages to
proposed-updates, where they get added after review by
the Stable Release Managers. The current list of packages can be seen at
http://ftp-master.debian.org/proposed-updates.html.
If you wish to help test updates to packages before they are
formally added to a point release, you can do this by adding the
proposed-updates section to your
sources.list:
deb http://mirrors.kernel.org/debian squeeze-proposed-updates main contrib deb-src http://mirrors.kernel.org/debian squeeze-proposed-updates main contrib
The next time you run apt-get update, the
system will become aware of the packages in the
proposed-updates section and will consider them
when looking for packages to upgrade.
This is not strictly a new feature of Debian, but one that has not been given much exposure before.
Some packages from proposed-updates may also be made
available via the squeeze-updates mechanism.
This path will be used for updates which many users may wish to install
on their systems before the next point release is made, such as updates
to virus scanners and timezone data. All packages from
squeeze-updates will be included in point
releases.
Note that this replaces the functionality previously provided by the volatile.debian.org archive.
In order to use packages from squeeze-updates,
you can add an entry to your sources.list:
deb http://mirrors.kernel.org/debian squeeze-updates main contrib deb-src http://mirrors.kernel.org/debian squeeze-updates main contrib
The next time you run apt-get update, the
system will become aware of the packages in the
squeeze-updates section and will consider them
when looking for packages to upgrade.
When a new package is made available via squeeze-updates,
this will be announced on the debian-stable-announce mailing list.
The service provided by the backports.org repositories has been integrated in Debian infrastructure and is now an official Debian service, hosted at backports.debian.org.
With squeeze Debian provides official Live systems for the amd64 and i386 architectures.
A Debian Live system is a Debian system that can be booted directly
from removable media (CD-ROMs, DVDs, USB keys) or from another computer
over the network without the need of installation. The images are
produced by a tool named live-build, which can easily be used to
create custom live images. More information about the Debian Live project
can be found at http://live.debian.net/.
Debian GNU/Linux 6.0 is the first GNU/Linux distribution release ever to offer
comprehensive support for magnetic resonance imaging (MRI) based neuroimaging
research. It comes with up-to-date software for structural image analysis
(e.g. ants), diffusion imaging and
tractography (e.g. mrtrix), stimulus
delivery (e.g. psychopy), MRI
sequence development (e.g. odin), as
well as a number of versatile data processing and analysis suites (e.g.
nipype). Moreover, this release has
built-in support for all major neuroimaging data formats. See the Debian
Science and Debian Med
task pages for a comprehensive list of included software and the NeuroDebian webpage for further
information.
[1] With some modules from GNOME 2.32.
[2] This change implies that disk requirements for tasks selected through the debian installer have increased too. For more information please see the “Disk Space Needed for Tasks” chapter in the Installation Guide.
[3] These dependences are declared through the use of the header format specified in the Linux Standard Base (LSB)