System maintenance

Related articles
General recommendations
Regular system maintenance is necessary for the proper functioning of Arch over a period of time. Timely maintenance is a practice many users get accustomed to.
Check for errors
Failed systemd services
Check if any systemd services have failed:
$ systemctl --failed
See
systemd#Using units
for more information.
Log files
Look for errors in the log files located in
/var/log/
, as well as messages logged in the systemd
journal
:
# journalctl -b
See
Xorg#Troubleshooting
for information on where and how
Xorg
logs errors.
Backup
Having backups of important data is a necessary measure to take, since human and machine processing errors are very likely to generate corruption as time passes, and also the physical media where the data is stored is inevitably destined to fail.
See
Synchronization and backup programs
for many alternative applications that may better suit your case. See
Category:System recovery
for other articles of interest.
It is highly encouraged to automate backups and test the recovery process to ensure everything works as intended. For automation see
System backup#Automation
.
Configuration files
Before editing any configuration files, create a backup so that you can revert to a working version in case of problems. Editors like
vim
and
emacs
can do this automatically. On a larger scale, consider using a
configuration manager
.
For
dotfiles
(configuration files in the home directory), see
dotfiles#Tracking dotfiles directly with Git
.
List of installed packages
Maintain a list of all installed packages so that if a complete re-installation is inevitable, it is easier to re-create the original environment.
See
pacman/Tips and tricks#List of installed packages
for details.
Pacman database
See
pacman/Tips and tricks#Back up the pacman database
.
Encryption metadata
See
Data-at-rest encryption#Backup for disk encryption scenarios
.
System and user data
See
System backup
.
Upgrading the system
It is recommended to perform full system upgrades regularly via
pacman#Upgrading packages
, to enjoy both the latest bug fixes and security updates, and also to avoid having to deal with too many package upgrades that require manual intervention at once. When requesting support from the community, it will usually be assumed that the system is up to date.
Make sure to have the Arch install media or another Linux "live" CD/USB available so you can easily rescue your system if there is a problem after updating. If you are running Arch in a production environment, or cannot afford downtime for any reason, test changes to configuration files, as well as updates to software packages, on a non-critical duplicate system first. Then, if no problems arise, roll out the changes to the production system.
If the system has packages from the
AUR
, carefully upgrade all of them.
pacman
is a powerful package management tool, but it does not attempt to handle all corner cases. Users must be vigilant and take responsibility for maintaining their own system.
Read before upgrading the system
Before upgrading, users are expected to visit the
Arch Linux home page
to check the latest news, or alternatively subscribe to the
RSS feed
or the
arch-announce mailing list
. When updates require out-of-the-ordinary user intervention (more than what can be handled simply by following the instructions given by
pacman
), an appropriate news post will be made.
Before upgrading fundamental software (such as the
kernel
,
xorg
,
systemd
, or
glibc
) to a new version, look over the appropriate
forum
to see if there have been any reported problems.
Users must equally be aware that upgrading packages can raise
unexpected
problems that could need immediate intervention; therefore, it is discouraged to upgrade a stable system shortly before it is required for carrying out an important task. Instead, wait to upgrade until there is enough time available to resolve any post-upgrade issues.
Tip
You could use a
pacman
hook like
informant
AUR
,
newscheck
AUR
or
arch-manwarn
AUR
which prevents you from updating if there is fresh Arch News that you have not read since the last update ran.
Avoid certain pacman commands
Avoid doing
partial upgrades
. In other words,
never
run
pacman -Sy
; instead,
always
use
pacman -Syu
.
Generally avoid using the
--overwrite
option with
pacman
. The
--overwrite
option takes an argument containing a glob. When used,
pacman
will bypass file conflict checks for files that match the glob. In a properly maintained system, it should only be used when explicitly recommended by the Arch Developers. See the
#Read before upgrading the system
section.
Avoid using the
-d
option with
pacman
.
pacman -Rdd
package
skips dependency checks during package removal. As a result, a package providing a critical dependency could be removed, resulting in a broken system.
Partial upgrades are unsupported
Arch Linux is a
rolling release
distribution. That means when new
library
versions are pushed to the repositories, the
Developers
and
Package Maintainers
rebuild all the packages in the repositories that need to be rebuilt against the libraries. For example, if two packages depend on the same library, upgrading only one package might also upgrade the library (as a dependency), which might then break the other package which depends on an older version of the library.
That is why partial upgrades are
not supported
. Do
not
use:
pacman -Sy
package
,
pacman -Sy
followed by
pacman -S
package
(instead,
-S
u
should be used in the installation of the package).
Note
pacman -Syuw
carries the same risks as
pacman -Sy
, because it will update the
pacman
sync database without installing the newer packages.
The bash script
checkupdates
, included with the
pacman-contrib
package, provides a safe way to check for upgrades to installed packages without running a system update, and provides an option (
-d
) to download the pending updates to the
pacman
cache without synchronizing the database, thus avoiding partial upgrade issues when later attempting to use
pacman -S
package
to install packages.
When refreshing the package database,
always
do a full upgrade with
pacman -Syu
.
Note
If
pacman -Syu
fails to complete the upgrade (i.e. the
-Su
part), the error must be
resolved
and the upgrade operation completed before other package management operations, as the database syncing (the
-Sy
part) has succeeded first.
Be very careful when using
IgnorePkg
and
IgnoreGroup
for the same reason. If the system has locally built packages (such as
AUR
packages), users will need to rebuild them when their dependencies receive a
soname
bump.
If a partial upgrade scenario has been created, and binaries are broken because they cannot find the libraries they are linked against,
do not "fix" the problem simply by symlinking
. Libraries receive
soname
bumps when they are
not backwards compatible
. A simple
pacman -Syu
to a properly synced mirror will fix the problem as long as
pacman
is not broken.
Act on alerts during an upgrade
When upgrading the system, be sure to pay attention to the alert notices provided by
pacman
. If any additional actions are required by the user, be sure to take care of them right away. If a
pacman
alert is confusing, search the forums or check the latest news on the Arch Linux homepage (see
#Read before upgrading the system
) for more detailed instructions.
Deal promptly with new configuration files
When
pacman
is invoked,
.pacnew
and
.pacsave
files can be created. Pacman provides notice when this happens and users must deal with these files promptly. Users are referred to the
pacman/Pacnew and Pacsave
wiki page for detailed instructions.
Also, think about other configuration files you may have copied or created. If a package had an example configuration that you copied to your home directory, check to see if a new one has been created.
Restart or reboot after upgrades
Upgrades are typically not applied to existing processes. You must restart processes to fully apply the upgrade.
The
archlinux-contrib
package provides a script called
checkservices
which runs
pacdiff
to merge
.pacnew
files then checks for processes running with outdated libraries and prompts the user if they want them to be restarted.
The kernel is particularly difficult to patch without a reboot. A reboot is always the most secure option, but if this is very inconvenient
kernel live patching
can be used to apply upgrades without a reboot.
Revert broken updates
If a package update is expected/known to cause problems, packagers will ensure that
pacman
displays an appropriate message when the package is updated. If experiencing trouble after an update, double-check the
pacman
output by looking at
/var/log/pacman.log
.
Tip
You can use a log viewer such as
wat-git
AUR
to search the pacman logs.
At this point, only after ensuring there is no information available through
pacman
, there is no relevant news on
https://archlinux.org/
, and there are no forum posts regarding the update, consider seeking help on the
forum
or over
IRC
.
Downgrading
the offending package to revert broken updates should be considered as a last resort.
Check for orphans and dropped packages
After upgrading you may now have packages that are no longer needed or that are no longer in the official repositories.
Use
pacman -Qtd
to check for packages that were installed as a dependency but now, no other packages depend on them. If an orphaned package is still needed, it is recommended to change the
installation reason
to explicit. Otherwise, if the package is no longer needed, it can be removed. See
pacman/Tips and tricks#Removing unused packages (orphans)
for details.
Additionally, some packages may no longer be in the remote repositories, but they still may be on your local system. To list all foreign packages use
pacman -Qm
. Note that this list will include packages that have been installed manually (e.g., from the
AUR
). To exclude packages that are (still) available on the AUR, use the script from
BBS#288205
or try the
ancient-packages
AUR
tool.
Check for firmware updates
In addition to software updates, firmware should also be updated regularly.
fwupd
is an extensive firmware update mechanism available for Linux systems.
Use the package manager to install software
Pacman
does a much better job than you at keeping track of files. If you install things manually you
will
, sooner or later, forget what you did, forget where you installed to, install conflicting software, install to the wrong locations, etc.
Install packages from the official repositories using the method in the
pacman#Installing packages
section.
If the program you desire is not available, check to see if someone has created a package in the
AUR
. Follow the method in that article for installation.
Lastly, if the program you want is not in the official repositories or in the AUR, learn how to
create a package
for it.
To clean up improperly installed files, see
pacman/Tips and tricks#Identify files not owned by any package
.
Choose open-source drivers
Always try open source drivers before resorting to proprietary drivers. Most of the time, open source drivers are more stable and reliable than proprietary drivers. Open source driver bugs are fixed more easily and quickly. While proprietary drivers can offer more features and capabilities, this can come at the cost of stability. To avoid this dilemma, try to choose hardware components known to have mature open source driver support with full features. Information about hardware with open source Linux drivers is available at
linux-drivers.org
.
Be careful with unofficial packages
Use precaution when using packages from the
AUR
or an
unofficial user repository
. Most are supplied by regular users and thus may not have the same standards as those in the official repositories.
Always
check PKGBUILDs for sanity and signs of mistake or malicious code before building and/or installing the package.
To simplify maintenance, limit the amount of unofficial packages used. Make periodic checks on which are in actual use, and remove (or replace with their official counterparts) any others. See
pacman/Tips and tricks#Maintenance
for useful commands. Following system upgrade, use
rebuild-detector
to identify any unofficial packages that may need to be rebuilt.
Update the mirrorlist
Update
pacman'
s mirrorlist, as the quality of mirrors can vary over time, and some might go offline or their download rate might degrade.
See
mirrors
for details.
Clean the filesystem
Programs that help with this can be found in
List of applications/Utilities#Disk cleaning
.
Unused large files
When looking for files to remove, it is important to find the files that take up the most disk space. Programs that help with this can be found in
List of applications/Utilities#Disk usage display
.
Package cache
Remove unwanted
.pkg
files from
/var/cache/pacman/pkg/
to free up disk space.
See
pacman#Cleaning the package cache
for more information.
Unused packages
Remove unused packages from the system to free up disk space and simplify maintenance.
See
#Check for orphans and dropped packages
.
Old configuration files
Old configuration files may conflict with newer software versions, or corrupt over time. Remove unneeded configurations periodically, particularly in your home directory and
~/.config
. For similar reasons, be careful when sharing home directories between installations.
Look for the following directories:
~/.config/
– where applications stores their configuration
~/.cache/
– cache of some programs may grow in size
~/.local/share/
– old files may be lying there
See
XDG Base Directory support
for more information about these directories.
To keep the home directory clean from temporary files created at the wrong place, it is a good idea to manage a list of unwanted files and remove them regularly, for example with
rmshit.py
.
rmlint-git
AUR
can be used to find and optionally remove duplicate files, empty files, recursive empty directories and broken symlinks.
Broken symlinks
Old, broken symbolic links might be sitting around your system; you should remove them. Examples on achieving this can be found
here
and
here
. However, you should not blindly delete all broken symbolic links, as some of them serve a purpose
[1]
.
To quickly list all the broken symlinks of permanent files on your system, use:
# find / -type d \( -path "/dev" -o -path "/proc" -o -path "/run" -o -path "/sys" \) -prune -o -xtype l -print
Then inspect and remove unnecessary entries from this list.
Tips and tricks
The following tips are generally not required, but certain users may find them useful.
Use proven software packages
Arch's rolling releases can be a boon for users who want to try the latest features and get upstream updates as soon as possible, but they can also make system maintenance more difficult. To simplify maintenance and improve stability, try to avoid cutting edge software and install only mature and proven software. Such packages are less likely to receive difficult upgrades such as major configuration changes or feature removals. Prefer software that has a strong and active development community, as well as a high number of competent users, in order to simplify support in the event of a problem.
Avoid any use of the testing repository, even individual packages from testing. These packages are experimental and not suitable for a stable system. Similarly, avoid packages which are built directly from upstream development sources. These are usually found in the
AUR
, with names including things like: "dev", "devel", "svn", "cvs", "git", etc.
Install the linux-lts package
The
linux-lts
package is an alternative Arch kernel package, and is available in the
core
repository. This particular kernel version has long-term support (LTS) from upstream, including security and bug fixes. It is useful if you use out-of-tree kernel modules and want to ensure their compatibility or if you want a fallback kernel in case a new kernel version causes problems.
To make it available as a boot option, you will need to update your
boot loader
's configuration file to use the LTS kernel and ram disk:
vmlinuz-linux-lts
and
initramfs-linux-lts.img
.
See also
Arch News Bash Script
fwupd