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出门在外也不愁Chapter 4. Upgrades from Debian 7 (wheezy)Chapter 4. Upgrades from Debian 7 (wheezy)Table of Contents4.1. Preparing for the upgrade
We suggest that before upgrading you also read the information in .
That chapter covers potential issues which are not directly
related to the upgrade process but could still be important to know about
before you begin.
4.1.1. Back up any data or configuration information
Before upgrading your system, it is strongly recommended that you make a full
backup, or at least back up any data or configuration information you can't
afford to lose.
The upgrade tools and process are quite reliable, but a
hardware failure in the middle of an upgrade could result in a severely damaged
The main things you'll want to back up are the contents of
/etc, /var/lib/dpkg,
/var/lib/apt/extended_states and the output of
dpkg --get-selections "*" (the quotes are important).
you use aptitude to manage packages on your system, you
will also want to back up /var/lib/aptitude/pkgstates.
The upgrade process itself does not modify anything in the
/home directory.
However, some applications (e.g.
of the Mozilla suite, and the GNOME and KDE desktop environments) are known to
overwrite existing user settings with new defaults when a new version of the
application is first started by a user.
As a precaution, you may want to make
a backup of the hidden files and directories (“dotfiles”) in users' home
directories.
This backup may help to restore or recreate the old settings.
You may also want to inform users about this.
Any package installation operation must be run with superuser privileges, so
either log in as root or use su or sudo to
gain the necessary access rights.
The upgrade has you should check them before actually
executing the upgrade.
4.1.2. Inform users in advance
It's wise to inform all users in advance of any upgrades you're planning,
although users accessing your system via an ssh connection
should notice little during the upgrade, and should be able to continue
If you wish to take extra precautions, back up or unmount the
/home partition before upgrading.
You will have to do a kernel upgrade when upgrading to jessie, so a
reboot will be necessary.
Typically, this will be done after the upgrade is finished.
4.1.3. Prepare for downtime on services
There might be services that are offered by the system which are associated with packages
that will be included in the upgrade. If this is the case, please note that,
during the upgrade, these services will be stopped while their associated packages
are being replaced and configured. During this time, these services will not be
available.
The precise downtime for these services will vary depending on the number of
packages being upgraded in the system, and it also includes the time the system
administrator spends answering any configuration questions from package
Notice that if the upgrade process is left unattended and
the system requests input during the upgrade there is a high
possibility of services being unavailable for a significant period of time.
If the system being upgraded provides critical services for your users or the
network, you can reduce the downtime if
you do a minimal system upgrade, as described in , followed by a kernel upgrade and reboot,
and then upgrade the packages associated with your
critical services. Upgrade these packages
prior to doing the full upgrade
described in .
This way you can ensure that
these critical services are running and available through the full upgrade
process, and their downtime is reduced.
4.1.4. Prepare for recovery
Although Debian tries to ensure that your system stays bootable at all times,
there is always a chance that you may experience problems
rebooting your system after the upgrade.
Known potential issues are
documented in this and the next chapters of these Release Notes.
For this reason it makes sense to ensure that you will be able to recover if
your system should fail to reboot or, for remotely managed systems, fail to
bring up networking.
If you are upgrading remotely via an ssh link it is
recommended that you take the necessary precautions to be able to access the
server through a remote serial terminal.
There is a chance that, after
upgrading the kernel and rebooting, you will have to fix the system
configuration through a local console.
Also, if the system is rebooted
accidentally in the middle of an upgrade there is a chance you will need to
recover using a local console.
Generally we recommend using the rescue
mode of the jessie Debian Installer.
The advantage of using the
installer is that you can choose between its many methods to find one
that best suits your situation.
For more information, please consult the
section “Recovering a Broken System” in chapter 8 of the
If that fails, you will need an alternative way to boot your system so you can
access and repair it.
One option is to use a special rescue image or a Linux
After booting from that, you should be able to mount your root file
system and chroot into it to investigate and fix the
4.1.4.1. Debug shell during boot using initrd
The initramfs-tools package includes a debug
shell in the
initrds it generates.
If for example the initrd is unable to mount your root
file system, you will be dropped into this debug shell which has basic commands
available to help trace the problem and possibly fix it.
Basic things to check are: presence of correct device files in
/dev; what modules are loaded (cat
/proc/modules); output of dmesg for errors loading
The output of dmesg will also show what device
files have been ass you should check that against the
output of echo $ROOT to make sure that the root file system
is on the expected device.
If you do manage to fix the problem, typing exit will quit
the debug shell and continue the boot process at the point it failed.
course you will also need to fix the underlying problem and regenerate the
initrd so the next boot won't fail again.
4.1.4.2. Debug shell during boot using systemd
If the boot fails under systemd, it is possible to obtain a
debug root shell by changing the kernel command line.
basic boot succeeds, but some services fail to start, it
may be useful to add systemd.unit=rescue.target
to the kernel parameters.
Otherwise, the kernel parameter
systemd.unit=emergency.target will provide you
with a root shell at the earliest possible point.
However, this
is done before mounting the root file system with read-write
permissions.
You will have to do that manually with:
mount -o remount,rw /
More information on debugging a broken boot under systemd
can be found in the
If everything else fails, you might be able to boot via the old
sysvinit system.
This requires that sysvinit is still installed and the
binary /lib/sysvinit/init is included in your
initramfs.
If these requirements are met, add
init=/lib/sysvinit/init on the kernel
command-line and it will boot with the sysvinit binary.
4.1.5. Prepare a safe environment for the upgrade
The distribution upgrade should be done either locally from a textmode virtual
console (or a directly connected serial terminal), or remotely via an
If you are using some VPN services (such as tinc) they might not be available
throughout the upgrade process. Please see
In order to gain extra safety margin when upgrading remotely, we suggest that
you run upgrade processes in the virtual console provided by the
screen program, which enables safe reconnection and ensures
the upgrade process is not interrupted even if the remote connection process
You should not upgrade using telnet,
rlogin, rsh, or from an X
session managed by xdm, gdm
or kdm etc. on the machine you are upgrading.
That is because each of those services may well be terminated
during the upgrade, which can result in an
inaccessible system that is only half-upgraded.
Use of the GNOME application update-manager is
strongly discouraged for upgrades to new releases, as
this tool relies on the desktop session remaining active.
4.2. Checking system status
The upgrade process described in this chapter has been designed for upgrades
from “pure” wheezy systems without third-party packages.
For the greatest reliability of the
upgrade process, you may wish to remove third-party packages from your system
before you begin upgrading.
Direct upgrades from Debian releases older than 7 (wheezy)
are not supported.
Please follow the instructions in the
to upgrade to 7 first.
This procedure also assumes your system has been updated to the latest point
release of wheezy.
If you have not done this or are unsure, follow the
instructions in .
4.2.1. Review actions pending in package manager
In some cases, the use of apt-get for installing packages
instead of aptitude might make aptitude
consider a package as “unused” and schedule it for removal.
In general, you
should make sure the system is fully up-to-date and “clean” before proceeding
with the upgrade.
Because of this you should review if there are any pending actions in the
package manager aptitude.
If a package is scheduled for
removal or update in the package manager, it might negatively impact the
upgrade procedure.
Note that correcting this is only possible if your
sources.list still points to wheezy
and not to stable or jessie; see .
To perform this review, launch aptitude in “visual mode” and
press g (“Go”).
If it shows any actions, you should review them and either fix
them or implement the suggested actions.
If no actions are suggested you will
be presented with a message saying “No packages are scheduled to be installed,
removed, or upgraded”.
4.2.2. Disabling APT pinning
If you have configured APT to install certain packages from a distribution
other than stable (e.g.
from testing), you may have to change your APT pinning
configuration (stored in /etc/apt/preferences and /etc/apt/preferences.d/) to allow
the upgrade of packages to the versions in the new stable release.
information on APT pinning can be found in apt_preferences(5).
4.2.3. Checking packages status
Regardless of the method used for upgrading, it is recommended that you check
the status of all packages first, and verify that all packages are in an
upgradable state.
The following command will show any packages which have a
status of Half-Installed or Failed-Config, and those with any error status.
# dpkg --audit
You could also inspect the state of all packages on your system using
aptitude or with commands such
# dpkg -l | pager
# dpkg --get-selections "*" & ~/curr-pkgs.txt
It is desirable to remove any holds before upgrading.
If any package that is
essential for the upgrade is on hold, the upgrade will fail.
Note that aptitude uses a different method for registering
packages that are on hold than apt-get and
You can identify packages on hold for
aptitude with
# aptitude search "~ahold"
If you want to check which packages you had on hold for
apt-get, you should use
# dpkg --get-selections | grep 'hold$'
If you changed and recompiled a package locally, and didn't rename it or put an
epoch in the version, you must put it on hold to prevent it from being
The “hold” package state for apt-get can be changed using:
# echo package_name hold | dpkg --set-selections
Replace hold with install to unset the
“hold” state.
If there is anything you need to fix, it is best to make sure your
sources.list still refers to wheezy as explained in .
4.2.4. The proposed-updates section
If you have listed the proposed-updates section
in your /etc/apt/sources.list file, you
should remove it from that file before attempting to upgrade your
This is a precaution to reduce the likelihood of
conflicts.
4.2.5. Unofficial sources
If you have any non-Debian packages on your system, you should be aware that
these may be removed during the upgrade because of conflicting dependencies.
If these packages were installed by adding an extra package archive in your
/etc/apt/sources.list, you should check if that archive
also offers packages compiled for jessie and change the source line accordingly
at the same time as your source lines for Debian packages.
Some users may have unofficial backported “newer” versions of packages that
are in Debian installed on their wheezy system.
packages are most likely to cause problems during an upgrade as they may result
in file conflicts.
has some information on how to deal with file
conflicts if they should occur.
4.3. Preparing sources for APT
Before starting the upgrade you must set up apt's configuration file for package lists,
/etc/apt/sources.list.
apt will consider all packages that can
be found via any “deb” line, and install the package with the
highest version number, giving priority to the first line in the
file (thus where you have multiple mirror locations, you'd typically first name a local
hard disk, then CD-ROMs, and then HTTP/FTP mirrors).
A release can often be referred to both by its codename (e.g.
wheezy, jessie) and by
its status name (i.e. oldstable, stable,
testing, unstable).
Referring to
a release by its codename has the advantage that you will never be surprised by
a new release and for this reason is the approach taken here.
It does of
course mean that you will have to watch out for release announcements yourself.
If you use the status name instead, you will just see loads of updates for
packages available as soon as a release has happened.
4.3.1. Adding APT Internet sources
The default configuration is set up for installation from the main Debian Internet
servers, but you may wish to modify /etc/apt/sources.list
to use other mirrors, preferably a mirror that is closest to you in network terms.
Debian HTTP or FTP mirror addresses can be found at
(look at the “list of Debian
mirrors” section).
HTTP mirrors are generally speedier than FTP mirrors.
For example, suppose your closest Debian mirror is
http://mirrors.kernel.org.
When inspecting that
mirror with a web browser or FTP program, you will notice that the main
directories are organized like this:
http://mirrors.kernel.org/debian/dists/jessie/main/binary-i386/...
http://mirrors.kernel.org/debian/dists/jessie/contrib/binary-i386/...
To use this mirror with apt, you add this line to your
sources.list file:
deb http://mirrors.kernel.org/debian jessie main contrib
Note that the “dists” is added implicitly, and the arguments
after the release name are used to expand the path into multiple directories.
After adding your new sources, disable the previously existing
“deb” lines in sources.list by placing a
hash sign (#) in front of them.
4.3.2. Adding APT sources for a local mirror
Instead of using HTTP or FTP package mirrors, you may wish to modify
/etc/apt/sources.list to use a mirror on a local disk
(possibly mounted over NFS).
For example, your package mirror may be under
/var/ftp/debian/, and have main directories like this:
/var/ftp/debian/dists/jessie/main/binary-i386/...
/var/ftp/debian/dists/jessie/contrib/binary-i386/...
To use this with apt, add this line to your
sources.list file:
deb file:/var/ftp/debian jessie main contrib
Note that the “dists” is added implicitly, and the arguments
after the release name are used to expand the path into multiple directories.
After adding your new sources, disable the previously existing
“deb” lines in sources.list by placing a
hash sign (#) in front of them.
4.3.3. Adding APT sources from optical media
If you want to use only CDs (or DVDs or Blu-ray Discs),
comment out the existing
“deb” lines in /etc/apt/sources.list by
placing a hash sign (#) in front of them.
Make sure there is a line in /etc/fstab that enables
mounting your CD-ROM drive at the /media/cdrom
mount point.
For example, if /dev/sr0
is your CD-ROM drive, /etc/fstab should contain a line
/dev/sr0 /media/cdrom auto noauto,ro 0 0
Note that there must be no spaces between the words
noauto,ro in the fourth field.
To verify it works, insert a CD and try running
# mount /media/cdrom
# this will mount the CD to the mount point
# ls -alF /media/cdrom
# this should show the CD's root directory
# umount /media/cdrom
# this will unmount the CD
Next, run:
# apt-cdrom add
for each Debian Binary CD-ROM you have, to add the data about each CD to APT's
4.4. Upgrading packages
The recommended way to upgrade from previous Debian releases is to
use the package management tool apt-get.
In previous
releases, aptitude was recommended for this purpose, but
recent versions of apt-get provide equivalent
functionality and also have shown to more consistently give the desired
upgrade results.
Don't forget to mount all needed partitions (notably the root and
/usr partitions) read-write, with a command like:
# mount -o remount,rw /mountpoint
Next you should double-check that the APT source entries (in
/etc/apt/sources.list) refer either to
“jessie” or to “stable”.
There should not be
any sources entries pointing to wheezy.
Source lines for a CD-ROM might sometimes refer to
“unstable”; although this may be confusing, you
should not change it.
4.4.1. Recording the session
It is strongly recommended that you use the /usr/bin/script
program to record a transcript of the upgrade session.
Then if a problem
occurs, you will have a log of what happened, and if needed, can provide exact
information in a bug report.
To start the recording, type:
# script -t 2&~/upgrade-jessiestep.time -a ~/upgrade-jessiestep.script
or similar. If you have to rerun the typescript (e.g. if you have to reboot the
system) use different step values to indicate which
step of the upgrade you are logging. Do not put the typescript file in a
temporary directory such as /tmp or
/var/tmp (files in those directories may be deleted during
the upgrade or during any restart).
The typescript will also allow you to review information that has scrolled
off-screen.
If you are at the system's console, just switch to VT2 (using
and, after logging in, use
less -R ~root/upgrade-jessie.script to view
After you have completed the upgrade, you can stop script by
typing exit at the prompt.
If you have used the -t switch for
script you can use the scriptreplay
program to replay the whole session:
# scriptreplay ~/upgrade-jessie.time ~/upgrade-jessie.script
4.4.2. Updating the package list
First the list of available packages for the new release needs to be fetched.
This is done by executing:
# apt-get update
4.4.3. Make sure you have sufficient space for the upgrade
You have to make sure before upgrading your system that you will have sufficient
hard disk space when you start the full system upgrade described in .
First, any package needed for installation that
is fetched from the network is stored in
/var/cache/apt/archives (and the
partial/ subdirectory, during download), so you must make
sure you have enough space on the file system partition that holds
/var/ to temporarily download the packages that will be
installed in your system.
After the download, you will probably need more
space in other file system partitions in order to both install upgraded
packages (which might contain bigger binaries or more data) and new packages
that will be pulled in for the upgrade.
If your system does not have
sufficient space you might end up with an incomplete upgrade that is
difficult to recover from.
apt-get can show you detailed information about the disk
space needed for the installation.
Before executing the upgrade, you can see
this estimate by running:
# apt-get -o APT::Get::Trivial-Only=true dist-upgrade
XXX upgraded, XXX newly installed, XXX to remove and XXX not upgraded.
Need to get xx.xMB of archives.
After this operation, AAAMB of additional disk space will be used.
Running this command at the beginning of the upgrade process
may give an error, for the reasons described in the next sections.
case you will need to wait until you've done the minimal system upgrade as in
before running this command to estimate the
disk space.
If you do not have enough space for the upgrade, apt-get
will warn you with a message like this:
E: You don't have enough free space in /var/cache/apt/archives/.
In this situation, make sure you free up space
beforehand.
Remove packages that have been previously downloaded for installation (at
/var/cache/apt/archives).
Cleaning up the package cache by
running apt-get clean will remove all previously downloaded
package files.
Remove forgotten packages.
If you have
used aptitude or apt-get to manually
install packages in wheezy it will have kept track of those packages
you manually installed, and will be able to mark as redundant those packages
pulled in by dependencies alone which are no longer needed due to a package
being removed. They will not mark for removal packages that you manually
installed. To remove automatically installed packages that are no longer used,
# apt-get autoremove
You can also use deborphan, debfoster, or
cruft to find redundant packages.
Do not blindly remove the packages these tools present,
especially if you are using aggressive non-default options that are prone to
false positives.
It is highly recommended that you manually review the
packages suggested for removal (i.e.
their contents, sizes, and descriptions)
before you remove them.
Remove packages that take up too much space and are not currently
needed (you can always reinstall them after the upgrade).
If you have
popularity-contest installed, you can use
popcon-largest-unused to list the packages you do not use
that occupy the most space.
You can find the packages that just
take up the most disk space with dpigs (available in the
debian-goodies package) or with
wajig (running wajig size).
They can also be found with
aptitude in “visual mode”,
select Views → New Flat Package
List, press l and enter
~i, then press S and enter
~installsize.
This will give you a handy list to work
Remove translations and localization files from the system if they
are not needed.
You can install the localepurge package and configure it so
that only a few selected locales are kept in the system. This will
reduce the disk space consumed at
/usr/share/locale.
Temporarily move to another system, or permanently remove, system logs
residing under /var/log/.
Use a temporary /var/cache/apt/archives: You
can use a temporary cache directory from another filesystem
(USB storage device, temporary hard disk,
filesystem already in use, ...)
Do not use an NFS mount as the network
connection could be interrupted during the upgrade.
For example, if you have a USB drive mounted on /media/usbkey:
remove the packages that have been previously downloaded for
installation:
# apt-get clean
copy the directory
/var/cache/apt/archives to the
USB drive:
# cp -ax /var/cache/apt/archives /media/usbkey/
mount the temporary cache directory on the current one:
# mount --bind /media/usbkey/archives /var/cache/apt/archives
after the upgrade, restore the original
/var/cache/apt/archives directory:
# umount /media/usbkey/archives
remove the remaining /media/usbkey/archives.
You can create the temporary cache directory on whatever filesystem
is mounted on your system.
Do a minimal upgrade of the system (see )
or partial upgrades of the system followed by a full upgrade.
This will make it possible to upgrade the system partially, and
allow you to clean the package cache before the full upgrade.
Note that in order to safely remove packages, it is advisable to switch your
sources.list back to wheezy as described in .
4.4.4. Minimal system upgrade
In some cases, doing the full upgrade (as described below) directly might
remove large numbers of packages that you will want to keep.
We therefore
recommend a two-part upgrade process: first a minimal upgrade to overcome these
conflicts, then a full upgrade as described in .
To do this, first run:
# apt-get upgrade
The upgrade process for some previous releases recommended the
use of aptitude for the upgrade. This
tool is not recommended for upgrades from wheezy to
This has the effect of upgrading those packages which can be upgraded without
requiring any other packages to be removed or installed.
The minimal system upgrade can also be useful when the system is tight on space
and a full upgrade cannot be run due to space constraints.
If the apt-listchanges package is
installed, it will (in its default configuration) show important information
about upgraded packages in a pager.
Press q after reading
to exit the pager and continue the upgrade.
4.4.5. Upgrading the system
Once you have taken the previous steps, you are now ready to continue
with the main part of the upgrade.
# apt-get dist-upgrade
The upgrade process for some previous releases recommended the
use of aptitude for the upgrade. This
tool is not recommended for upgrades from wheezy to
This will perform a complete upgrade of the system, installing the newest
available versions of all packages, and resolving all possible dependency changes
between packages in different releases.
If necessary, it will install some new
packages (usually new library versions, or renamed packages), and remove any
conflicting obsoleted packages.
When upgrading from a set of CD-ROMs (or DVDs), you will be asked to insert specific CDs
at several points during the upgrade.
You might have to insert the same CD
this is due to inter-related packages that have been spread out
over the CDs.
New versions of currently installed packages that cannot be upgraded without
changing the install status of another package will be left at their current
version (displayed as “held back”).
This can be resolved by either using
aptitude to choose these packages for installation or by
trying apt-get install
4.5. Possible issues during upgrade
The following sections describe known issues that might appear
during an upgrade to jessie.
4.5.1. Dist-upgrade fails with “Could not perform immediate configuration”
In some cases the apt-get dist-upgrade step can fail after
downloading packages with:
E: Could not perform immediate configuration on 'package'.
Please see man 5 apt.conf under APT::Immediate-Configure for details.
If that happens, running apt-get dist-upgrade -o
APT::Immediate-Configure=0 instead should allow the upgrade
to proceed.
Another possible workaround for this problem is to temporarily add both
wheezy and jessie sources to your
sources.list and run apt-get update.
4.5.2. Expected removals
The upgrade process to jessie might ask for the removal of
packages on the system. The precise list of packages will vary depending on the
set of packages that you have installed.
These release notes give general
advice on these removals, but if in doubt, it is recommended that you examine
the package removals proposed by each method before proceeding.
For more information about packages obsoleted in jessie, see .
4.5.3. Conflicts or Pre-Depends loops
Sometimes it's necessary to enable the APT::Force-LoopBreak
option in APT to be able to temporarily remove an essential package due to a
Conflicts/Pre-Depends loop.
apt-get will alert you of this
and abort the upgrade.
You can work around this by specifying the option -o
APT::Force-LoopBreak=1 on the apt-get command
It is possible that a system's dependency structure can be so corrupt as to
require manual intervention.
Usually this means using
apt-get or
# dpkg --remove package_name
to eliminate some of the offending packages, or
# apt-get -f install
# dpkg --configure --pending
In extreme cases you might have to force re-installation with a command like
# dpkg --install /path/to/package_name.deb
4.5.4. File conflicts
File conflicts should not occur if you upgrade from a “pure” wheezy system, but
can occur if you have unofficial backports installed.
A file conflict will
result in an error like:
Unpacking &package-foo& (from &package-foo-file&) ...
dpkg: error processing &package-foo& (--install):
trying to overwrite `&some-file-name&',
which is also in package &package-bar&
dpkg-deb: subprocess paste killed by signal (Broken pipe)
Errors were encountered while processing:
&package-foo&
You can try to solve a file conflict by forcibly removing the package mentioned
on the last line of the error message:
# dpkg -r --force-depends package_name
After fixing things up, you should be able to resume the upgrade by repeating
the previously described apt-get commands.
4.5.5. Configuration changes
During the upgrade, you will be asked questions regarding the configuration
or re-configuration of several packages.
When you are asked if any file in
the /etc/init.d directory, or the
/etc/manpath.config file should be replaced by the
package maintainer's version, it's usually necessary to answer “yes” to
ensure system consistency.
You can always revert to the old versions, since
they will be saved with a .dpkg-old extension.
If you're not sure what to do, write down the name of the package or file and
sort things out at a later time.
You can search in the typescript file to
review the information that was on the screen during the upgrade.
4.5.6. Change of session to console
If you are running the upgrade using the system's local console you
might find that at some points during the upgrade the console is shifted over
to a different view and you lose visibility of the upgrade
For example, this may happen in desktop systems when
the display manager is restarted.
To recover the console where the upgrade was running you will have to use
Ctrl+Alt+F1
(if in the graphical startup screen) or
(if in the local text-mode console) to switch back to the virtual terminal 1.
Replace F1 with the function key with the
same number as the virtual terminal the upgrade was running in. You can also
use Alt+Left Arrow or
Arrow to switch between the different text-mode terminals.
4.5.7. Special care for specific packages
In most cases, packages should upgrade smoothly between wheezy
and jessie.
There are a small number of cases where some intervention
may be required, either before o these are detailed
below on a per-package basis.
4.5.7.1. systemd
The Debian upgrade from wheezy to jessie
will by default migrate your init system from the SysV to systemd.
Depending on your system and setup, you may need to do some
manual changes.
We have detailed known issues in .
4.5.7.2. LXC
If you have LXC installed, you may need special care when
upgrading your system and your containers.
Please have a
issues and solutions.
4.6. Upgrading your kernel and related packages
This section explains how to upgrade your kernel and identifies potential
issues related to this upgrade.
You can either install one of the linux-image-* packages provided by Debian, or
compile a customized kernel from source.
Note that a lot of information in this section is based on the assumption that
you will be using one of the modular Debian kernels, together with initramfs-tools and udev.
If you choose to use a custom kernel that
does not require an initrd or if you use a different initrd generator, some of
the information may not be relevant for you.
4.6.1. Installing a kernel metapackage
When you dist-upgrade from wheezy to jessie, it is
strongly recommended that you install a linux-image-* metapackage, if
you have not done so before.
These metapackages will automatically
pull in a newer version of the kernel during upgrades.
You can verify
whether you have one installed by running:
# dpkg -l "linux-image*" | grep ^ii | grep -i meta
If you do not see any output, then you will either need to install a
new linux-image package by hand or install a linux-image metapackage.
To see a list of available linux-image metapackages, run:
# apt-cache search linux-image- | grep -i meta | grep -v transition
If you are unsure about which package to select, run uname
-r and look for a package with a similar name.
For example, if you
see '2.6.32-5-amd64', it is recommended that you install
linux-image-amd64.
You may also use apt-cache to see a long
description of each package in order to help choose the best one
available.
For example:
# apt-cache show linux-image-amd64
You should then use apt-get install to install it.
Once this new kernel is installed you should reboot at the next
available opportunity to get the benefits provided by the new kernel
However, please have a look at
before performing the first reboot after the upgrade.
For the more adventurous there is an easy way to compile your own custom
kernel on Debian.
Install the kernel sources, provided in the linux-source package.
You can make use of the
deb-pkg target available in the sources' makefile for
building a binary package.
More information can be found in the , which can also be found as the debian-kernel-handbook package.
If possible, it is to your advantage to upgrade the kernel package separately
from the main dist-upgrade to reduce the chances of a
temporarily non-bootable system.
Note that this should only be done after the
minimal upgrade process described in .
4.6.2. Changes to root and /usr filesystem mounting and checking
initramfs-tools will now also run
fsck on the root filesystem before mounting it.
If the chosen init program is systemd and there
is a separate /usr filesystem, it will also
fsck and mount /usr.
If /usr is a separate filesystem on a
RAID device and the INITRDSTART setting in
/etc/default/mdadm is not
'all', you will need to change it to
include that device.
If /usr is a separate filesystem on an
LVM logical volume, and the line for /usr
in /etc/fstab specifies the device by
UUID or LABEL, you must
change this line to specify the device using the format
/dev/mapper/VG-LV
/dev/VG/LV.
It is no longer possible to bind-mount the
/usr filesystem.
If the RTC (real time clock) is set to local time and the
local time is ahead of UTC, e2fsck will
print a warning during boot about the time changing backward
You can disable this by putting the
following lines in /etc/e2fsck.conf:
broken_system_clock=1
4.7. Things to do before rebooting
When apt-get dist-upgrade has finished, the “formal” upgrade
is complete, but there are some other things that should be taken care of
before the next reboot.
When upgrading from Wheezy to Jessie, it can be
a good idea to purge old packages before
the first reboot.
In particular, obsolete init scripts may
cause issues.
Please see
for details on finding and purging removed packages.
4.8. Preparing for the next release
After the upgrade there are several things you can do to prepare for the next
Remove newly redundant or obsolete packages as described in
You should review which configuration files they use and consider purging
the packages to remove their configuration files.
4.8.1. Purging removed packages
It is generally advisable to purge removed packages.
especially true if these have been removed in an earlier release
upgrade (e.g. from the upgrade to wheezy) or they were
provided by third-party vendors.
In particular, old init.d
scripts have been known to cause issues.
Purging a package will generally also purge its log files, so
you might want to back them up first.
The following command displays a list of all removed packages that
may have configuration files left on the system (if any):
# dpkg -l | awk '/^rc/ { print $2 }'
The packages can be removed by using apt-get
Assuming you want to purge all of them
in one go, you can use the following command:
# apt-get purge $(dpkg -l | awk '/^rc/ { print $2 }')
If you use aptitude, you
can also use the following alternative to the commands above:
$ aptitude search '~c'
$ aptitude purge '~c'
4.9. Deprecated components
With the next release of Debian 9 (codenamed
stretch) some features will be deprecated. Users
will need to migrate to other alternatives to prevent
trouble when updating to 9.
This includes the following features:
The hardening-wrapper package
is deprecated and is expected to be removed in Stretch.
4.10. Obsolete packages
Introducing lot of new packages, jessie also retires and omits quite some
old packages that were in wheezy.
It provides no upgrade path
for these obsolete packages.
While nothing prevents you from continuing to use
an obsolete package where desired, the Debian project will usually discontinue
security support for it a year after jessie's release, and will
not normally provide other support in the meantime.
Replacing them with
available alternatives, if any, is recommended.
There are many reasons why packages might have been removed from the
distribution: they are no longer there is no longer a
Debian Developer interested in main the functionality they
provide has been superseded by different software (or a new version); or they
are no longer considered suitable for jessie due to bugs in them.
In the latter
case, packages might still be present in the “unstable” distribution.
Detecting which packages in an updated system are “obsolete” is easy since the
package management front-ends will mark them as such.
If you are using
aptitude, you will see a listing of these packages in the
“Obsolete and Locally Created Packages” entry.
often provides additional information on why the package was removed.
should review both the archived bug reports for the package itself and the
archived bug reports for the .
The list of obsolete packages includes:
postgresql-9.1, successor is
postgresql-9.4.
Once the operating system
upgrade is finished, you should plan to also upgrade your PostgreSQL
9.1 database clusters to the new PostgreSQL version 9.4 using the
pg_upgradecluster tool.
For users of the PL/perl procedural language, jessie provides an
updated postgresql-plperl-9.1
package linked against jessie's version of libperl in order to enable
upgrading to the new perl version in jessie while keeping
the old PL/perl database functions usable until the database is
upgraded as well.
python3.2, successor is
python3.4. (Version 2.7 is supported in
both wheezy and jessie.)
ruby1.8 and
ruby1.9.1; successor is
Please install the package
ruby to automatically track the current ruby version.
mplayer; alternatives are
and mpv (new in jessie).
Whilst the former is mostly compatible with mplayer in terms of command-line
arguments and configuration (and adds a few new features too), the
latter adds a lot of new features and improvements, and it is actively
maintained upstream.
openoffice.org; please use
libreoffice.
squid, successor is
libjpeg-progs, successor is
libjpeg-turbo-progs.
openjdk-6-*, successor is
openjdk-7-*.
4.10.1. Dummy packages
Some packages from wheezy have been split into several packages in jessie, often
to improve system maintainability.
To ease the upgrade path in such cases,
jessie often provides “dummy” packages: empty packages that have the same name as
the old package in wheezy with dependencies that cause the new packages to be
installed.
These “dummy” packages are considered redundant after the
upgrade and can be safely removed.
Most (but not all) dummy packages' descriptions indicate their purpose.
Package descriptions for dummy packages are not uniform, however, so you might
also find deborphan with the
--guess-* options (e.g.
--guess-dummy) useful to detect them in your system.
that some dummy packages are not intended to be removed after an upgrade but
are, instead, used to keep track of the current available version of a program
over time.}