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Snippets for yer computer needs

SystemD

systemctl

Command Notes
systemctl List services
start SERVICE Used to start a service (not reboot persistent)
stop SERVICE Used to stop a service (not reboot persistent)
restart SERVICE Used to stop and then start a service
reload SERVICE When supported, reloads the config file without interrupting pending operations
condrestart SERVICE Restarts if the service is already running
status SERVICE Tells whether a service is currently running
enable SERVICE Turn the service on, for start at next boot, or other trigger
disable SERVICE Turn the service off for the next reboot, or any other trigger
is-enabled SERVICE Used to check whether a service is configured to start or not in the current environment
list-unit-files –type=service Print a table of services that lists which runlevels each is configured on or off
daemon-reload Used when you create a new service file or modify any configuration
list-dependencies Show dependency tree of a target

journalctl

# Jump to the end of the log
journalctl -e
# Use the message catalog for explanatory text
journalctl -x
# Show kernel logs of previous boot
journalctl -k -b -1
# Tail the log of a service
journalctl -u SERVICENAME -f

Directories

Runlevels

To change the runlevel at boot, add the following to the kernel arguments, e.g. systemd.unit=rescue.target

To change the runlevel in a running system, systemctl isolate rescue.target

target desc
poweroff.target halt/shut off system
rescue.target single user mode
multi-user.target normal startup of system
graphical.target graphical startup
reboot.target restart system

Mountpoints

Links