SysVinit to Systemd Cheatsheet

From FedoraProject

(Difference between revisions)
Jump to: navigation, search
Line 13: Line 13:
 
| chkconfig frobozz || systemctl is-enabled frobozz.service || Used to check whether a service is configured to start or not in the current environment.
 
| chkconfig frobozz || systemctl is-enabled frobozz.service || Used to check whether a service is configured to start or not in the current environment.
 
|-
 
|-
| chkconfig frobozz --list || || Used to list what levels this service is configured on or off
+
| chkconfig frobozz --list || ls /etc/systemd/system/*.target.wants/frobozz.service || Used to list what levels this service is configured on or off
 
|-
 
|-
 
| chkconfig frobozz --level 345 on || systemctl enable frobozz.service OR ln -s ../frobozz.service /lib/systemd/system/runlevel3.target.wants/ to configure runlevels manually || Turn the service on for the next reboot
 
| chkconfig frobozz --level 345 on || systemctl enable frobozz.service OR ln -s ../frobozz.service /lib/systemd/system/runlevel3.target.wants/ to configure runlevels manually || Turn the service on for the next reboot

Revision as of 21:31, 18 October 2010

This is a document to help system administrators who need to understand what commands in systemd replace their old workflow in SysVinit.

Note that the 'service' and 'chkconfig' commands will continue to work as expected in the systemd world, this guide is how to use the native systemctl calls that are being made by those commands.

Services

SystemVinit Command Systemd Command Notes
ls /etc/rc.d/init.d/ ls /lib/systemd/system/*.service Used to list the services that can be started or stopped
chkconfig frobozz systemctl is-enabled frobozz.service Used to check whether a service is configured to start or not in the current environment.
chkconfig frobozz --list ls /etc/systemd/system/*.target.wants/frobozz.service Used to list what levels this service is configured on or off
chkconfig frobozz --level 345 on systemctl enable frobozz.service OR ln -s ../frobozz.service /lib/systemd/system/runlevel3.target.wants/ to configure runlevels manually Turn the service on for the next reboot
chkconfig frobozz --level 345 off systemctl disable frobozz.service OR rm /lib/systemd/system/runlevel3.target.wants/frobozz.service to configure runlevels manually Turn the service off for the next reboot
service frobozz start systemctl start frobozz.service (OR service frobozz start) Used to start a service (not reboot persistent)
service frobozz stop systemctl stop frobozz.service (OR service frobozz stop) Used to stop a service (not reboot persistent)
service frobozz restart systemctl restart frobozz.service (OR service frobozz restart) Used to stop and then start a service
service frobozz reload systemctl reload frobozz.service (OR service frobozz reload) When supported, reloads the config file without interrupting pending operations.
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.
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

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.

SystemVinit 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:

SystemVinit 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/systemd/multi-user.target /etc/systemd/system/default.target Set to use multi-user runlevel on next reboot.