Chapter 2. What's new in Debian 7.0

The official Debian distribution now ships on 9 to 10 binary DVDs or 61 to 69 binary CDs (depending on the architecture) and 8 source DVDs or 46 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 is also released as Blu-ray (BD) images, 2 each for the amd64 and i386 architectures, or 2 for the source code. For size reasons, some very large packages are omitted from the CD builds; these packages fit better in the DVD and BD builds, so are still included there.

New in Debian 7.0 is multiarch. Multiarch lets you install packages from multiple architectures on the same machine. This is useful in various ways, but the most common is installing both 64 and 32-bit software on the same machine and having dependencies correctly resolved automatically. The Debian wiki has an extensive manual on how to make use of this functionality if you need it.

The dependency-based boot sequencing introduced with Debian 6.0 is now always enabled, including for users of file-rc.

For optimal sequencing, all init.d scripts should declare their dependencies in an LSB header. This is already the case for scripts shipped in Debian, but users should check their local scripts and consider adding that information.

For more information on this feature refer to the information available in /usr/share/doc/insserv/README.Debian.

Debian 7.0 introduces preliminary support for systemd, an init system with advanced monitoring, logging and service management capabilities.

While it is designed as a drop-in sysvinit replacement and as such makes use of existing SysV init scripts, the systemd package can be installed safely alongside sysvinit and started via the init=/bin/systemd kernel option. To utilize the features provided by systemd, about 50 packages already provide native support, among them core packages like udev, dbus and rsyslog.

systemd is shipped as a technology preview in Debian 7.0. For more information on this topic, see the Debian wiki.

Debian wheezy comes with improved multimedia support: ffmpeg has been replaced by the libav fork (libav-tools), which is considered to feature a more conservative release process and thus fit better to Debian's needs. It provides all libraries and prepares an upgrade path for existing application packages. The full-featured libav libraries and frontends include e.g. mplayer, mencoder, vlc and transcode. Additional codec support is provided e.g. through lame for MP3 audio encoding, xvidcore for MPEG-4 ASP video encoding, x264 for H.264/MPEG-4 AVC video encoding, vo-aacenc for AAC audio encoding and opencore-amr and vo-amrwbenc for Adaptive Multi-Rate Narrowband and Wideband encoding and decoding, respectively. For most use cases, installation of packages from third-party repositories should not be necessary anymore. The times of crippled multimedia support in Debian are finally over!

Many Debian packages have now been built with gcc compiler hardening flags enabled. These flags enable various protections against security issues such as stack smashing, predictable locations of values in memory, etc. An effort has been made to ensure that as many packages as possible include these flags, especially focusing on those in the 'base'-installation, network-accessible daemons and packages which have had security issues in recent years.

Note that the hardened build flags are not enabled by default in gcc, so are not used automatically when locally building software. The package hardening-wrapper can provide a gcc with these flags enabled.

Debian 7.0 supports the AppArmor Mandatory Access Control system. When enabled, AppArmor confines programs according to a set of rules that specify what files a given program can access. This proactive approach helps protecting the system against both known and unknown vulnerabilities.

AppArmor is disabled by default in Debian 7.0. The Debian wiki has instructions on how to use this functionality.

Note that this replaces the functionality previously provided by the backports.debian.org archive.

In order to use packages from wheezy-backports, you can add an entry to your sources.list:

deb     http://mirrors.kernel.org/debian wheezy-backports main contrib
deb-src http://mirrors.kernel.org/debian wheezy-backports main contrib

The next time you run apt-get update, the system will become aware of the packages in the wheezy-backports section and they will be available for installation in the same way as the old backports.debian.org archive.

When a new package is made available via wheezy-backports to fix a security issue, this will be announced on the debian-backports-announce mailing list.

Some packages from proposed-updates may also be made available via the wheezy-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 wheezy-updates will be included in point releases.

In order to use packages from wheezy-updates, you can add an entry to your sources.list:

deb     http://mirrors.kernel.org/debian wheezy-updates main contrib
deb-src http://mirrors.kernel.org/debian wheezy-updates main contrib

The next time you run apt-get update, the system will become aware of the packages in the wheezy-updates section and will consider them when looking for packages to upgrade.

Note that if APT::Default-Release is set in your /etc/apt/apt.conf (or in any of /etc/apt/apt.conf.d/*), then, in order for automatic upgrades to work, it is necessary to add the following configuration block into /etc/apt/preferences (see apt_preferences(5) for more information):

Package: *
Pin: release o=Debian,n=wheezy-updates
Pin-Priority: 990

When a new package is made available via wheezy-updates, this will be announced on the debian-stable-announce mailing list.

GNOME has undergone a major interface rewrite in the upgrade to version 3.4. The traditional GNOME panel has been replaced by the “shell”, an innovative interface with major usability improvements.

Among other things, it features dynamic workspaces, an on-screen keyboard (Caribou), instant messaging built into the interface, and integration with the GNOME keyring and PolicyKit.

If you want to keep an interface closer to the GNOME 2.30 version in wheezy, you can select the “GNOME Classic” session at the login prompt. It will bring you an improved version of the traditional panel. You can still edit the panel to add more applets, by using the hidden alt+right click combination.

If your hardware is not compatible with the GNOME shell's requirements, you will also be redirected to the “classic” interface.

Debian 7.0 includes the OpenStack suite as well as the Xen Cloud Platform (XCP), allowing users to deploy their own cloud infrastructure.

Debian images are also provided on the major public cloud platforms, including Amazon EC2, Windows Azure and Google Compute Engine.

In previous releases, temporary (tmpfs) filesystems were mounted on /lib/init/rw, /dev/shm/ and optionally on /var/lock and /var/run. /lib/init/rw has been removed, and the others have been moved under /run. /var/run and /var/lock were configured using RAMRUN and RAMLOCK in /etc/default/rcS. All these tmpfs filesystems are now configurable using /etc/default/tmpfs; the old settings are not migrated automatically.

The migration of data to the new locations will occur automatically during the upgrade and will continue to be available at the old and new locations, with the exception of /lib/init/rw. No action is required on your part, though you may wish to customize which tmpfs filesystems are mounted, and their size limits, in /etc/default/tmpfs after the upgrade is complete. Please see the tmpfs(5) manual page for further details.

If you have written any custom scripts which make use of /lib/init/rw, these must be updated to use /run instead.

/tmp is not a tmpfs by default. If you chose to use this feature, please note that: