systemd
zh-CN:Systemd Template:Article summary start Template:Article summary text Template:Article summary heading Template:Article summary wiki Template:Article summary wiki Template:Article summary wiki - systemd and udev have been merged upstream. Template:Article summary end From the project web page:
"systemd is a system and service manager for Linux, compatible with SysV and LSB init scripts. systemd provides aggressive parallelization capabilities, uses socket and D-Bus activation for starting services, offers on-demand starting of daemons, keeps track of processes using Linux control groups, supports snapshotting and restoring of the system state, maintains mount and automount points and implements an elaborate transactional dependency-based service control logic. It can work as a drop-in replacement for sysvinit."
See also the Wikipedia article.
Contents
- 1 Things to consider before you switch
- 2 Installation
- 3 Native systemd configuration files
- 4 Systemd commands
- 5 Runlevels/targets
- 6 Running DEs under systemd
- 7 Systemd Journal
- 8 Network
- 9 Arch integration
- 10 Writing custom .service files
- 11 FAQ
- 12 Optimization
- 13 Troubleshooting
- 14 See also
Things to consider before you switch
- It is highly recommended to switch to the new initscripts configuration system described in the rc.conf article. Once you have this configuration established, you will have done most of the work needed to make the switch to systemd.
- Do some reading about systemd.
- Note the fact that systemd has a journal system that replaces syslog, although the two can co-exist. See the section on the journal below.
- Do not worry about systemd's plans to replace the functionality of cron, acpid, or xinetd. These are not things you need to worry about just yet. For now, you can continue to use your traditional daemons for these tasks.
Installation
systemd can be installed side-by-side with the regular Arch Linux initscripts package, and they can be toggled by adding/removing the init=/bin/systemd
kernel parameter.
A pure systemd installation
- Install systemd from the official repositories.
- Add
init=/bin/systemd
to the kernel parameters in your bootloader. - Create systemd configuration files.
- Enable daemons formerly listed in
/etc/rc.conf
withsystemctl enable daemonname.service
. For a translation of the daemons from/etc/rc.conf
to systemd services, see: List of Daemons and Services - Reboot. Your system should now initialize with systemd. If you are satisfied, remove the
init=...
entry. - Install systemd-sysvcompat. This conflicts with sysvinit, and will prompt you to remove it.
A mixed systemd installation
- Install systemd from the official repositories
- Add
init=/bin/systemd
to the kernel parameters in your bootloader. - We recommend that you use native systemd configuration files instead of Arch's classic configuration files. You can still use
/etc/rc.conf
to configure a few variables if the native configuration files do not exist, but support will be dropped in the future. - If you want to keep using syslog log files alongside the systemd journal, follow the instructions described in the section on the journal, below.
Supplementary information
quiet
in your kernel parameters, you should remove it for your first couple of systemd boots, to assist with identifying any issues during boot./usr
must be mounted and available at bootup (this is not particular to systemd). If your /usr
is on a separate partition, you will need to make accommodations to mount it from the initramfs and unmount it from a pivoted root on shutdown. See the mkinitcpio wiki page and freedesktop.org#separate-usr-is-broken.Native systemd configuration files
systemd will use /etc/rc.conf
if these files are absent. Note this is temporary and not a long-term solution. It is strongly advised to use the systemd configuration files on any system.
Hostname
/etc/hostname
myhostname
Console and keymap
The /etc/vconsole.conf
file configures the virtual console, i.e. keyboard mapping and console font.
/etc/vconsole.conf
KEYMAP=us FONT=lat9w-16 FONT_MAP=8859-1_to_uni
For more info see Console fonts and Keymap.
/etc/vconsole.conf
KEYMAP= FONT=
This might be the default in the future.
Locale
Read man locale.conf
for more options:
/etc/locale.conf
LANG=en_US.UTF-8 LC_COLLATE=C
For more info see Locale.
Time zone
Read man 5 localtime
for more options.
# ln -sf /usr/share/zoneinfo/America/Chicago /etc/localtime
or, if you want to use a relative symlink:
# ln -sf ../usr/share/zoneinfo/America/Chicago /etc/localtime
/etc/timezone
has been deprecated in systemd-190
and can/should be deleted.Hardware clock time
Systemd will use UTC for the hardware clock by default and this is recommended. Dealing with daylight saving time is messy. If the DST changes when your computer is off, your clock will be wrong on next boot (there is a lot more to it). Recent kernels set the system time from the RTC directly on boot without using hwclock
, the kernel will always assume that the RTC is in UTC. This means that if the RTC is in local time, then the system time will first be set up wrongly and then corrected shortly afterwards on every boot. This is possibly the reason for certain weird bugs (time going backwards is rarely a good thing).
The reason for allowing the RTC to be in local time is to allow dual boot with Windows (which uses localtime). Windows is able to deal with the RTC being in UTC with a simple registry fix. If you run into issues on dual boot with Windows, you can set the hardware clock to local time. Contrary to popular belief, systemd supports this:
/etc/adjtime
0.0 0.0 0.0 0 LOCAL
The other parameters are still needed but are ignored by systemd.
It is generally advised to have a Network Time Protocol daemon running to keep the hardware clock synchronized with the system time.
Kernel modules loaded during boot
systemd uses /etc/modules-load.d/
to configure kernel modules to load during boot in a static list. Each configuration file is named in the style of /etc/modules-load.d/<program>.conf
. The configuration files should simply contain a list of kernel module names to load, separated by newlines. Empty lines and lines whose first non-whitespace character is #
or ;
are ignored. Example:
/etc/modules-load.d/virtio-net.conf
# Load virtio-net.ko at boot virtio-net
See also Modprobe#Options.
Kernel modules blacklist
Module blacklisting works the same way as with initscripts since it is actually handled by kmod. See Module Blacklisting for details.
Temporary files
Systemd-tmpfiles uses the configuration files in /usr/lib/tmpfiles.d/
and /etc/tmpfiles.d/
to describe the creation, cleaning and removal of volatile and temporary files and directories which usually reside in directories such as /run
or /tmp
. Each configuration file is named in the style of /etc/tmpfiles.d/<program>.conf
. This will also override any files in /usr/lib/tmpfiles.d/
with the same name.
tmpfiles are usually provided together with service files to create directories which are expected to exist by certain daemons. For example the Samba daemon expects the directory /var/run/samba
to exist and to have the correct permissions. The corresponding tmpfile looks like this:
/usr/lib/tmpfiles.d/samba.conf
D /var/run/samba 0755 root root
However, tmpfiles may also be used to write values into certain files on boot. For example, if you use /etc/rc.local
to disable wakeup from USB devices with echo USBE > /proc/acpi/wakeup
, you may use the following tmpfile instead:
/etc/tmpfiles.d/disable-usb-wake.conf
w /proc/acpi/wakeup - - - - USBE
The tmpfiles method is recommended in this case since systemd doesn't actually support /etc/rc.local
.
See man tmpfiles.d
for details.
Remote filesystem mounts
systemd automatically makes sure that remote filesystem mounts like NFS or Samba are only started after the network has been set up. Therefore remote filesystem mounts specified in /etc/fstab
should work out of the box.
You may however want to use Automount for remote filesystem mounts to mount them only upon access. Furthermore you can use the x-systemd.device-timeout=#
option in /etc/fstab
to specify a timeout in case the network resource is not available.
See man systemd.mount
for details.
ACPI Power Management with systemd
Systemd handles some power-related ACPI events. This is configured via the following options in /etc/systemd/logind.conf
:
-
HandlePowerKey
: specifies which action is invoked when the power key is pressed -
HandleSuspendKey
: specifies which action is invoked when the suspend key is pressed -
HandleHibernateKey
: specifies which action is invoked when the hibernate key is pressed -
HandleLidSwitch
: specifies which action is invoked when the lid is closed
The specified action can be one of ignore
, poweroff
, reboot
, halt
, suspend
, hibernate
or kexec
.
If these options are not configured, systemd will use it's defaults: HandlePowerKey=poweroff
, HandleSuspendKey=suspend
, HandleHibernateKey=hibernate
, and HandleLidSwitch=suspend
.
On systems which run no graphical setup or only a simple window manager like i3 or awesome, this may replace the acpid daemon which is usually used to react to these ACPI events.
ignore
or they will try to be handled twice."Inhibited" ACPI events
In the current version of systemd, the Handle
options will apply throughout the system unless they are "inhibited" (temporarily turned off) by a program, such as a power manager inside a desktop environment. If you want systemd to always handle these events, you can tell it to ignore the inhibited signals with the following options in /etc/systemd/logind.conf
:
PowerKeyIgnoreInhibited
SuspendKeyIgnoreInhibited
HibernateKeyIgnoreInhibited
LidSwitchIgnoreInhibited
All of these default to no, except LidSwitchIgnoreInhibited
.
LidSwitchIgnoreInhibited=no
Sleep hooks
Systemd does not use pm-utils to put the machine to sleep when using systemctl suspend
or systemctl hibernate
, therefore pm-utils hooks including any custom hooks created will not be run. However, systemd provides a similar mechanism to run custom scripts on these events. Systemd runs all executables in /usr/lib/systemd/system-sleep/
and passes two arguments to each of them:
- Argument 1: either
pre
orpost
, depending on whether the machine is going to sleep or waking up - Argument 2: either
suspend
orhibernate
, depending on what has been invoked
In contrast to pm-utils, systemd will run these scripts in parallel and not one after another.
The output of your script will be logged by systemd-suspend.service
or systemd-hibernate.service
so you can see its output in the journal.
Note that you can also use sleep.target
, suspend.target
or hibernate.target
to hook units into the sleep state logic instead of using scripts.
See man systemd.special
and man systemd-sleep
for more information.
Example
/usr/lib/systemd/system-sleep/example.sh
#!/bin/sh case "$1" in pre ) echo going to $2 ... ;; post ) echo waking up from $2 ... ;; esac
Unit
A unit configuration file encodes information about a service, a socket, a device, a mount point, an automount point, a swap file or partition, a start-up target, a file system path or a timer controlled and supervised by systemd. The syntax is inspired by XDG Desktop Entry Specification .desktop files, which are in turn inspired by Microsoft Windows .ini files. See man systemd.unit
for more info.
Systemd commands
systemctl
: used to introspect and control the state of the systemd system and service manager.systemd-cgls
: recursively shows the contents of the selected Linux control group hierarchy in a treesystemadm
: a graphical frontend for the systemd system and service manager that allows introspection and control of systemd (available via the systemd-ui-gitAUR package from the AUR).
View the man pages for more details.
systemctl
commands with the -H <user>@<host>
switch to control a systemd instance on a remote machine. This will use SSH to connect to the remote systemd instance.Analyzing the system state
List running units:
$ systemctl
or:
$ systemctl list-units
List failed units:
$ systemctl --failed
The available unit files can be seen in /usr/lib/systemd/system/
and /etc/systemd/system/
(the latter takes precedence). You can see list installed unit files by:
$ systemctl list-unit-files
Using Units
Units can be, for example, services (.service
), mount points (.mount
), devices (.device
) or sockets (.socket
).
When using systemctl
, you generally have to specify the complete name of the unit file, including its suffix, for example sshd.socket
. There are however a few shortforms when specifying the unit in the following systemctl
commands:
- If you don't specify the suffix, systemctl will assume
.service
. For example,netcfg
andnetcfg.service
are treated equivalent.Note: This currently does not work with the commandsenable
anddisable
. - Mount points will automatically be translated into the appropriate
.mount
unit. For example, specifying/home
is equivalent tohome.mount
. - Similiar to mount points, devices are automatically translated into the appropriate
.device
unit, therefore specifying/dev/sda2
is equivalent todev-sda2.device
.
See man systemd.unit
for details.
Activate a unit immediately:
# systemctl start <unit>
Deactivate a unit immediately:
# systemctl stop <unit>
Restart a unit:
# systemctl restart <unit>
Ask a unit to reload its configuration:
# systemctl reload <unit>
Show the status of a unit, including whether it is running or not:
$ systemctl status <unit>
Check whether a unit is already enabled or not:
$ systemctl is-enabled <unit>
Enable a unit to be started on bootup:
# systemctl enable <unit>
# ln -s /usr/lib/systemd/system/foo.service /etc/systemd/system/graphical.target.wants/
Disable a unit to not start during bootup:
# systemctl disable <unit>
Show the manual page associated with a unit (this has to be supported by the unit file):
$ systemctl help <unit>
Power Management
If you are in a local systemd-logind
or ConsoleKit user session and no other session is active, the following commands will work without root privileges. If not (for example, because another user is logged into a tty), systemd will automatically ask you for the root password (see also Replacing ConsoleKit with systemd-logind).
Shut down and reboot the system:
$ systemctl reboot
Shut down and power-off the system:
$ systemctl poweroff
Shut down and halt the system:
$ systemctl halt
Suspend the system:
$ systemctl suspend
Hibernate the system:
$ systemctl hibernate
Runlevels/targets
Runlevels is a legacy concept in systemd. Systemd uses targets which serve a similar purpose as runlevels but act a little different. Each target is named instead of numbered and is intended to serve a specific purpose with the possibility of having multiple ones active at the same time. Some targets are implemented by inheriting all of the services of another target and adding additional services to it. There are systemd targets that mimic the common SystemVinit runlevels so you can still switch targets using the familiar telinit RUNLEVEL
command.
Get current runlevel/targets
The following should be used under systemd instead of runlevel
:
# systemctl list-units --type=target
Create custom target
The runlevels that are assigned a specific purpose on vanilla Fedora installs; 0, 1, 3, 5, and 6; have a 1:1 mapping with a specific systemd target. Unfortunately, there is no good way to do the same for the user-defined runlevels like 2 and 4. If you make use of those it is suggested that you make a new named systemd target as /etc/systemd/system/<your target>
that takes one of the existing runlevels as a base (you can look at /usr/lib/systemd/system/graphical.target
as an example), make a directory /etc/systemd/system/<your target>.wants
, and then symlink the additional services from /usr/lib/systemd/system/
that you wish to enable.
Targets table
SysV Runlevel | Systemd Target | Notes |
---|---|---|
0 | runlevel0.target, poweroff.target | Halt the system. |
1, s, single | runlevel1.target, rescue.target | Single user mode. |
2, 4 | runlevel2.target, runlevel4.target, multi-user.target | User-defined/Site-specific runlevels. By default, identical to 3. |
3 | runlevel3.target, multi-user.target | Multi-user, non-graphical. Users can usually login via multiple consoles or via the network. |
5 | runlevel5.target, graphical.target | Multi-user, graphical. Usually has all the services of runlevel 3 plus a graphical login. |
6 | runlevel6.target, reboot.target | Reboot |
emergency | emergency.target | Emergency shell |
Change current runlevels
In systemd runlevels are exposed via "target units". You can change them like this:
# systemctl isolate graphical.target
This will only change the current runlevel, and has no effect on the next boot. This is equivalent to commands such as telinit 3
or telinit 5
in Sysvinit.
Change default runlevel/target to boot into
The standard target is default.target
, which is aliased by default to graphical.target
(which roughly corresponds to the old runlevel 5). To change the default target at boot-time, append one of the following kernel parameters to your bootloader:
-
systemd.unit=multi-user.target
(which roughly corresponds to the old runlevel 3), -
systemd.unit=rescue.target
(which roughly corresponds to the old runlevel 1).
Alternatively, you may leave the bootloader alone and change default.target
. This can be done using systemctl
:
# systemctl enable multi-user.target
The effect of this command is outputted by systemctl
; a symlink to the new default target is made at /etc/systemd/system/default.target
. This works if, and only if:
[Install] Alias=default.target
is in the target's configuration file. Currently, multi-user.target
and graphical.target
both have it.
Running DEs under systemd
Using display manager
To enable graphical login, run your preferred Display Manager daemon (e.g. KDM). At the moment, service files exist for GDM, KDM, SLiM, XDM, LXDM and LightDM.
# systemctl enable kdm.service
This should work out of the box. If not, you might have a default.target
set manually or from a older install:
# ls -l /etc/systemd/system/default.target
/etc/systemd/system/default.target -> /usr/lib/systemd/system/graphical.target
Simply delete the symlink and systemd will use its stock default.target
(i.e. graphical.target
).
# rm /etc/systemd/system/default.target
Using service file
If you are only looking for a simple way to start X directly without a display manager, you can create a service file similar to this:
/etc/systemd/system/graphical.target.wants/xinit.service
[Unit] Description=Direct login to X After=systemd-user-sessions.service [Service] ExecStart=/bin/su <username> -l -c "/bin/bash --login -c xinit" [Install] WantedBy=graphical.target
Systemd Journal
Since version 38 systemd has an own logging system, the journal.
By default, running a syslog daemon is no longer required. To read the log, use:
# journalctl
The journal writes to /run/systemd/journal
, meaning logs will be lost on reboot. For non-volatile logs, create /var/log/journal/
:
# mkdir /var/log/journal/
Filtering output
journalctl
allows you to filter the output by specific fields.
Examples:
Show all messages by a specific executable:
# journalctl /usr/lib/systemd/systemd
Show all messages by a specific process:
# journalctl _PID=1
Show all messages by a specific unit:
# journalctl _SYSTEMD_UNIT=netcfg.service
See man journalctl
and systemd.journal-fields
for details.
Journal size limit
If the journal is made non-volatile, its size limit is set to a default value of 10% of the size of the respective file system. E.g. with /var/log/journal
located on a 50 GiB root partition this would lead to 5 GiB of journal data. The maximum size of the persistent journal can be controlled by SystemMaxUse
in /etc/systemd/journald.conf
, so to limit it for example to 50 MiB uncomment and edit the corresponding line to:
SystemMaxUse=50M
Refer to man journald.conf
for more info.
Journald in conjunction with a classic syslog daemon
Compatibility with classic syslog implementations is provided via a
socket /run/systemd/journal/syslog
, to which all messages are forwarded.
To make the syslog daemon work with the journal, it has to bind to this socket instead of /dev/log
(official announcement). For syslog-ng, change the source src
section in /etc/syslog-ng/syslog-ng.conf
to:
source src { unix-dgram("/run/systemd/journal/syslog"); internal(); file("/proc/kmsg"); };
and enable syslog-ng:
# systemctl enable syslog-ng.service
Network
Dynamic (DHCP) with dhcpcd
If you simply want to use DHCP for your Ethernet connection, you can use dhcpcd@.service
(provided by the dhcpcd package).
To enable DHCP for eth0
, simply use:
# systemctl start dhcpcd@eth0.service
You can enable the service to automatically start at boot with:
# systemctl enable dhcpcd@eth0.service
Other configurations
For static, wireless or advanced network configuration like bridging you can use netcfg or NetworkManager which both provide systemd service files.
If you need a static Ethernet configuration, but don't want to use netcfg, there is a custom service file available on the Systemd/Services page.
Arch integration
Initscripts emulation
Integration with Arch's classic configuration is provided by the initscripts package. This is simply meant as a transitional measure to ease users' move to systemd.
/etc/inittab
is not used at all.If you disabled Template:Keypress to reboot in /etc/inittab
, you will have to reconfigure this setting for systemd by running systemctl mask ctrl-alt-del.target
as root.
rc.conf
Some variables in /etc/rc.conf
are respected by this glue work. For a pure systemd setup, it is recommended to use the native systemd configuration files which will take precedence over /etc/rc.conf
.
Supported variables:
-
LOCALE
-
KEYMAP
-
CONSOLEFONT
-
CONSOLEMAP
-
HOSTNAME
-
DAEMONS
Not supported variables and systemd configuration:
-
TIMEZONE
: Please symlink/etc/localtime
to your zoneinfo file manually. -
HARDWARECLOCK
: See Hardware clock time. -
USELVM
: uselvm.service
provided by lvm2 instead. -
USECOLOR
-
MODULES
Total conversion to native systemd
rc.conf
centralised configuration anymore, but uses native systemd configuration files.Follow system configuration as explained in #Native_systemd_configuration_files. Each file replaces one section of /etc/rc.conf
as shown in that table:
Configuration | Configuration file(s) | Legacy /etc/rc.conf section
|
---|---|---|
Hostname | /etc/hostname
|
NETWORKING
|
Console fonts and Keymap | /etc/vconsole.conf
|
LOCALIZATION
|
Locale | /etc/locale.conf
|
LOCALIZATION
|
Time zone | /etc/localtime
|
LOCALIZATION
|
Hardware clock | /etc/adjtime
|
LOCALIZATION
|
Kernel modules | /etc/modules-load.d/
|
HARDWARE
|
For legacy purposes, the DAEMONS section in /etc/rc.conf
is still compatible with systemd and can be used to start services at boot, even with a "pure" systemd service management. Alternatively, you may remove the /etc/rc.conf
file entirely and enable services in systemd. For each <service_name>
in the DAEMONS array in /etc/rc.conf
, type:
# systemctl enable <service_name>.service
If <service_name>.service
does not exist:
- the service file may not be available for systemd. In that case, you'll need to keep
rc.conf
to start the service during boot up. - systemd may name services differently, e.g.
cronie.service
replacescrond
init daemon;alsa-store.service
andalsa-restore.service
replace thealsa
init daemon. Another important instance is thenetwork
daemon, which is replaced with another set of service files (see #Network for more details.)
$ pacman -Ql cronie [...] cronie /etc/rc.d/crond #<-- daemon initscript listed in the DAEMONS array (unused in a "pure" systemd configuration) [...] cronie /usr/lib/systemd/system/cronie.service #<-- corresponding systemd daemon service [...]
- systemd will automatically handle the start order of these daemons.
- some services do not need to be explicitly enabled by the user. For instance,
dbus.service
will automatically be enabled whendbus-core
is installed. Check the list of available services and their state using thesystemctl
command.
Writing custom .service files
Handling dependencies
With systemd, dependencies can be resolved by designing the unit files correctly. The most typical case is that the unit A
requires the unit B
to be running before A
is started. In that case add Requires=B
and After=B
to the [Unit]
section of A
. If the dependency is optional, add Wants=B
and After=B
instead. Note that Wants=
and Requires=
do not imply After=
, meaning that if After=
is not specified, the two units will be started in parallel.
Dependencies are typically placed on services and not on targets. For example, network.target
is pulled in by whatever service configures your network interfaces, therefore ordering your custom unit after it is sufficient since network.target
is started anyway.
Type
There are several different start-up types to consider when writing a custom service file. This is set with the Type=
parameter in the [Service]
section. See man systemd.service
for a more detailed explanation.
-
Type=simple
: systemd considers the service to be started up immediately. The process must not fork. Do not use this type if other services need to be ordered on this service, unless it is socket activated. -
Type=forking
: systemd considers the service started up once the process forks and the parent has exited. For classic daemons use this type unless you know that it is not necessary. You should specifyPIDFile=
as well so systemd can keep track of the main process. -
Type=oneshot
: This is useful for scripts that do a single job and then exit. You may want to setRemainAfterExit=
as well so that systemd still considers the service as active after the process has exited. -
Type=notify
: Identical toType=simple
, but with the stipulation that the daemon will send a signal to systemd when it is ready. The reference implementation for this notification is provided bylibsystemd-daemon.so
. -
Type=dbus
: The service is considered ready when the specifiedBusName
appears on DBus's system bus.
Replacing provided unit files
The unit files in /etc/systemd/system/
take precedence over the ones in /usr/lib/systemd/system/
.
To make your own version of a unit (which will not be destroyed by an upgrade), copy the old unit file from /usr/lib/
to /etc/
and make your changes there. Alternatively you can use .include
to parse an existing service file and then override or add new options. For example, if you simply want to add an additional dependency to a service file, you may use:
/etc/systemd/system/<service-name>.service
.include /usr/lib/systemd/system/<service-name>.service [Unit] Requires=<new dependency> After=<new dependency>
Then run the following for your changes to take effect:
# systemctl reenable <unit> # systemctl restart <unit>
systemd-delta
to see which unit files have been overridden and what exactly has been changed.Syntax highlighting for systemd unit files within Vim
Syntax highlighting for systemd unit files within Vim can be enabled by installing vim-systemdAUR from the AUR.
FAQ
For an up-to-date list of known issues, look at the upstream TODO.
Optimization
systemd-analyze
Systemd provides a tool called systemd-analyze
that allows you to analyze your boot process so you can see which unit files are causing your boot process to slow down. You can then optimize your system accordingly. You have to install python2-dbus and python2-cairo to use it.
To see how much time was spent in kernel-/userspace on boot, simply use:
$ systemd-analyze
timestamp
hook to your HOOKS
array in /etc/mkinitcpio.conf
and rebuild your initramfs, systemd-analyze
will also be able to show you how much time was spent in the initramfs.To list the started unit files, sorted by the time each of them took to start up:
$ systemd-analyze blame
You can also create a SVG file which describes your boot process grapically, similiar to Bootchart:
$ systemd-analyze plot > plot.svg
Enabling bootchart in conjunction with systemd
You can use a version of bootchart to visualize the boot sequence. Since you are not able to put a second init into the kernel command line you won't be able to use any of the standard bootchart setups. However the bootchart2AUR package from AUR comes with an undocumented systemd service. After you've installed bootchart2 do:
# systemctl enable bootchart.service
Read the bootchart documentation for further details on using this version of bootchart.
Shell Shortcuts
systemd daemon management requires a bit more text entry to accomplish tasks such as start, stopped, enabling, checking status, etc. The following functions can be added to one's ~/.bashrc
file to help streamline interactions with systemd and to improve the overall experience.
if ! systemd-notify --booted; then # not using systemd start() { sudo rc.d start $1 } restart() { sudo rc.d restart $1 } stop() { sudo rc.d stop $1 } else start() { sudo systemctl start $1 } restart() { sudo systemctl restart $1 } stop() { sudo systemctl stop $1 } enable() { sudo systemctl enable $1 } status() { sudo systemctl status $1 } disable() { sudo systemctl disable $1 } fi
Less output
Change verbose
to quiet
on the bootloader's kernel line. For some systems, particularly those with an SSD, the slow performance of the TTY is actually a bottleneck, and so less output means faster booting.
Early start
One central feature of systemd is D-Bus and socket activation, this causes services to be started when they are first accessed, and is generally a good thing. However, if you know that a service (like ConsoleKit) will always be started during boot, then the overall boot time might be reduced by starting it as early as possible. This can be achieved (if the service file is set up for it, which in most cases it is) by issuing:
# systemctl enable console-kit-daemon.service
This will cause systemd to start ConsoleKit as soon as possible, without causing races with the socket or D-Bus activation.
Automount
The default setup will fsck and mount all filesystems before starting most daemons and services. If you have a large /home
partition, it might be better to allow services that do not depend on /home
to start while /home
is being fsck'ed. This can be achieved by adding the following options to the fstab entry of your /home
partition:
noauto,x-systemd.automount
This will fsck and mount /home
when it is first accessed, and the kernel will buffer all file access to /home
until it is ready.
If you have encrypted filesystems with keyfiles, you can also add the noauto
parameter to the corresponding entries in /etc/crypttab
. systemd will then not open the encrypted device on boot, but instead wait until it is actually accessed and then automatically open it with the specified keyfile before mounting it. This might save a few seconds on boot if you are using an encrypted RAID device for example, because systemd doesn't have to wait for the device to become available. For example:
/etc/crypttab
data /dev/md0 /root/key noauto
Readahead
systemd comes with its own readahead implementation, this should in principle improve boot time. However, depending on your kernel version and the type of your hard drive, your mileage may vary (i.e. it might be slower). To enable, do:
# systemctl enable systemd-readahead-collect.service systemd-readahead-replay.service
Remember that in order for the readahead to work its magic, you should reboot a couple of times.
Replacing ConsoleKit with systemd-logind
Starting with polkit 0.107 (currently in [testing]), ConsoleKit can be completely replaced by systemd-logind
. However, there is currently no Display Manager in the Arch Linux repositories which natively supports systemd-logind
without still depending on ConsoleKit. The easiest method to be able to remove ConsoleKit is to automatically login to a virtual console and start X from there. It is important that, as mentioned in the latter article, the X server is started on the same virtual console that you log in to, otherwise systemd can not keep track of the user session. You can then simply remove ck-launch-session
from your ~/.xinitrc
.
In order to check the status of your user session, you can use loginctl
. To see if your user session is properly set up, check if the following command contains Active=yes
. All polkit actions like suspending the system or mounting external drives with Udisks should then work automatically.
$ loginctl show-session <session-id>
--with-session-tracking=systemd
in the PKGBUILD.Troubleshooting
Shutdown/Reboot takes terribly long
If the shutdown process takes a very long time (or seems to freeze) most likely a service not exiting is to blame. systemd waits some time for each service to exit before trying to kill it. To find out if you are affected see this article.
SLiM and xfce-session
One setup that can produce a shutdown freeze is Xfce in conjunction with SLiM: Shutting down/rebooting using xfce-session will cause slim.service to hang for half a minute until systemd kills it the hard way.
One workaround is to create a modified slim.service
:
/etc/systemd/system/slim.service
[Unit] Description=SLiM Simple Login Manager After=systemd-user-sessions.service [Service] Type=forking PIDFile=/var/lock/slim.lock ExecStart=/usr/bin/slim -d ExecStop=/bin/kill -9 $MAINPID ExecStopPost=/bin/rm /var/lock/slim.lock [Install] WantedBy=graphical.target
This causes SLiM to be terminated using SIGKILL. Since the lock file is also removed this does not cause a problem.
If some services are failing to start
If your /var/tmp
is a symbolic link to /tmp
, expect some services to fail when started via systemd. In these cases, the failure status of the processes (via systemctl status <service>
) will be "226/NAMESPACE". To overcome this blocker, simply remove your /var/tmp
symlink and reinstall the filesystem package.
Disable warning bell
Add command xset -b
to the .xinitrc
file.
Discussion on this forum topic.
See also
- Official Web Site
- Manual Pages
- systemd Optimizations
- FAQ
- Tips And Tricks
- systemd for Administrators (PDF)
- About systemd on Fedora Project
- How to debug Systemd problems
- Booting up: Tools and tips for systemd, a Linux init tool. In The H
- Lennart's blog story
- status update
- status update2
- status update3
- most recent summary