SysVinit to Systemd Cheatsheet

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This is a document to help system administrators who need to understand what commands in systemd replace their old workflow in SysVinit.
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{{autolang|base=yes}}
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This is a document to help system administrators who need to understand what commands in systemd replace their old workflow in sysvinit.   If you want general information on systemd, refer to [[systemd]].
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{{admon/tip | Note on 'service' and 'chkconfig' commands | The 'service' and 'chkconfig' commands will mostly continue to work as expected in the systemd world, this guide is how to use the native
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systemctl replacements. }}
  
 
== Services ==
 
== Services ==
  
{|
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{|border="1" cellspacing="0"
!SystemVinit Command!!Systemd Command!!Notes
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!Sysvinit Command!!Systemd Command!!Notes
 
|-
 
|-
| ls -al /etc/rc.d/init.d || systemctl --all --type=service || Used to list the services that can be started or stopped
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| service frobozz start || systemctl start frobozz.service || Used to start a service (not reboot persistent)
|-|-
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| chkconfig frobozz --list || || Used to list what levels this service is configured on or off
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|-
 
|-
| chkconfig frobozz --level 345 on || || Turn the service on for the next reboot
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| service frobozz stop || systemctl stop frobozz.service || Used to stop a service (not reboot persistent)
 
|-
 
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| chkconfig frobozz --level 345 off || || Turn the service off for the next reboot
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| service frobozz restart || systemctl restart frobozz.service  || Used to stop and then start a service
 
|-
 
|-
| service frobozz start || systemctl start frobozz.service OR service frobozz start || Used to start a service (not reboot persistent)
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| service frobozz reload || systemctl reload frobozz.service || When supported, reloads the config file without interrupting pending operations.
 
|-
 
|-
| service frobozz stop || systemctl stop frobozz.service OR service frobozz stop || Used to stop a service (not reboot persistent)
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| service frobozz condrestart || systemctl condrestart frobozz.service || Restarts if the service is already running.
 
|-
 
|-
| service frobozz restart || systemctl restart frobozz.service OR service frobozz restart || Used to stop and then start a service
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| service frobozz status || systemctl status frobozz.service || Tells whether a service is currently running.
 
|-
 
|-
| service frobozz reload || systemctl reload frobozz.service OR service frobozz reload || When supported, reloads the config file without interrupting pending operations.
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| ls /etc/rc.d/init.d/ || systemctl list-unit-files --type=service (preferred)<br />ls /lib/systemd/system/*.service /etc/systemd/system/*.service|| Used to list the services that can be started or stopped <br /> Used to list all the services and other units
 
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| service frobozz condrestart || systemctl reload-or-restart frobozz.service OR systemctl condrestart frobozz.service OR service frobozz condrestart || When supported, restarts if the service is already running.
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| chkconfig frobozz on || systemctl enable frobozz.service || Turn the service on, for start at next boot, or other trigger.
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|-
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| chkconfig frobozz off || systemctl disable frobozz.service || Turn the service off for the next reboot, or any other trigger.
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|-
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| chkconfig frobozz || systemctl is-enabled frobozz.service || Used to check whether a service is configured to start or not in the current environment.
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|-
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| chkconfig --list || systemctl list-unit-files --type=service(preferred)<br/>ls /etc/systemd/system/*.wants/ || Print a table of services that lists which runlevels each is configured on or off
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|-
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| chkconfig frobozz --list || ls /etc/systemd/system/*.wants/frobozz.service || Used to list what levels this service is configured on or off
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|-
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| chkconfig frobozz --add || systemctl daemon-reload || Used when you create a new service file or modify any configuration
 
|-
 
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|}
 
|}
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Note that all /sbin/service and /sbin/chkconfig lines listed above continue to work on systemd, and will be translated to native equivalents as necessary. The only exception is chkconfig --list.
  
 
{{admon/warning|Additional commands|In SysVinit, services can define arbitrary commands. Examples would be '''service iptables panic''', or '''service httpd graceful'''. Native systemd services do not have this ability.
 
{{admon/warning|Additional commands|In SysVinit, services can define arbitrary commands. Examples would be '''service iptables panic''', or '''service httpd graceful'''. Native systemd services do not have this ability.
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Check the package-specific release notes for any services that may have done this.}}
 
Check the package-specific release notes for any services that may have done this.}}
  
== Runlevels ==
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== Runlevels/targets ==
  
runlevels are used with telinit and on the kernel command line in SystemVinit. These traditional ways of switching runlevels still work with systemd, but additionally, the following can be used instead.
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Systemd has a concept of ''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.  Some ''targets'' are implemented by inheriting all of the services of another ''target'' and adding additional services to it.  There are systemd ''target''s that mimic the common sysvinit runlevels so you can still switch ''target''s using the familiar <code>telinit RUNLEVEL</code> command. 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's 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 <code>/etc/systemd/system/$YOURTARGET</code> that takes one of the existing runlevels as a base (you can look at <code>/lib/systemd/system/graphical.target</code> as an example), make a directory <code>/etc/systemd/system/$YOURTARGET.wants</code>, and then symlink the additional services that you want to enable into that directory.  (The service unit files that you symlink live in <code>/lib/systemd/system</code>).
  
{|
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{|border="1" cellspacing="0"
!SystemVinit Runlevel!!Systemd Target!!Notes
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!Sysvinit Runlevel!!Systemd Target!!Notes
 
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|-
 
| 0 || runlevel0.target, poweroff.target || Halt the system.
 
| 0 || runlevel0.target, poweroff.target || Halt the system.
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Changing runlevels:
 
Changing runlevels:
  
{|
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{|border="1" cellspacing="0"
!SystemVinit Command!!Systemd Command!!Notes
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!Sysvinit Command!!Systemd Command!!Notes
 
|-
 
|-
| telinit 3 || systemctl isolate runlevel3.target OR telinit 3 || Change to multi-user run level.
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| telinit 3 || systemctl isolate multi-user.target (OR systemctl isolate runlevel3.target OR telinit 3) || Change to multi-user run level.
 
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|-
| sed s/^id:.*:initdefault:/id:3:initdefault:/ || ln -sf /lib/systemd/systemd/multi-user.target /etc/systemd/system/default.target || Set to use multi-user runlevel on next reboot.
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| sed s/^id:.*:initdefault:/id:3:initdefault:/ || ln -sf /lib/systemd/system/multi-user.target /etc/systemd/system/default.target || Set to use multi-user runlevel on next reboot.
 
|}
 
|}

Revision as of 03:37, 25 January 2013

This is a document to help system administrators who need to understand what commands in systemd replace their old workflow in sysvinit. If you want general information on systemd, refer to systemd.

Idea.png
Note on 'service' and 'chkconfig' commands
The 'service' and 'chkconfig' commands will mostly continue to work as expected in the systemd world, this guide is how to use the native systemctl replacements.

Services

Sysvinit Command Systemd Command Notes
service frobozz start systemctl start frobozz.service Used to start a service (not reboot persistent)
service frobozz stop systemctl stop frobozz.service Used to stop a service (not reboot persistent)
service frobozz restart systemctl restart frobozz.service Used to stop and then start a service
service frobozz reload systemctl reload frobozz.service When supported, reloads the config file without interrupting pending operations.
service frobozz condrestart systemctl condrestart frobozz.service Restarts if the service is already running.
service frobozz status systemctl status frobozz.service Tells whether a service is currently running.
ls /etc/rc.d/init.d/ systemctl list-unit-files --type=service (preferred)
ls /lib/systemd/system/*.service /etc/systemd/system/*.service
Used to list the services that can be started or stopped
Used to list all the services and other units
chkconfig frobozz on systemctl enable frobozz.service Turn the service on, for start at next boot, or other trigger.
chkconfig frobozz off systemctl disable frobozz.service Turn the service off for the next reboot, or any other trigger.
chkconfig frobozz systemctl is-enabled frobozz.service Used to check whether a service is configured to start or not in the current environment.
chkconfig --list systemctl list-unit-files --type=service(preferred)
ls /etc/systemd/system/*.wants/
Print a table of services that lists which runlevels each is configured on or off
chkconfig frobozz --list ls /etc/systemd/system/*.wants/frobozz.service Used to list what levels this service is configured on or off
chkconfig frobozz --add systemctl daemon-reload Used when you create a new service file or modify any configuration

Note that all /sbin/service and /sbin/chkconfig lines listed above continue to work on systemd, and will be translated to native equivalents as necessary. The only exception is chkconfig --list.

Warning (medium size).png
Additional commands
In SysVinit, services can define arbitrary commands. Examples would be service iptables panic, or service httpd graceful. Native systemd services do not have this ability.

Any service that defines an additional command in this way would need to define some other, service-specific, way to accomplish this task when writing a native systemd service definition.

Check the package-specific release notes for any services that may have done this.

Runlevels/targets

Systemd has a concept of 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. 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 sysvinit runlevels so you can still switch targets using the familiar telinit RUNLEVEL command. 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's 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/$YOURTARGET that takes one of the existing runlevels as a base (you can look at /lib/systemd/system/graphical.target as an example), make a directory /etc/systemd/system/$YOURTARGET.wants, and then symlink the additional services that you want to enable into that directory. (The service unit files that you symlink live in /lib/systemd/system).

Sysvinit 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

Changing runlevels:

Sysvinit Command Systemd Command Notes
telinit 3 systemctl isolate multi-user.target (OR systemctl isolate runlevel3.target OR telinit 3) Change to multi-user run level.
sed s/^id:.*:initdefault:/id:3:initdefault:/ ln -sf /lib/systemd/system/multi-user.target /etc/systemd/system/default.target Set to use multi-user runlevel on next reboot.