systemctl
systemctl is a cli to systemd. Reasonable intro.
The pager defaults to less. To disable it use --no-pager or
export SYSTEMD_PAGER=.
How to manage systemd units with systemctl
Unit Types
To list the unit (daemon) types:
$ systemctl -t help
Available unit types:
service
mount
swap
socket
target
device
automount
timer
path
slice
scope
| Unit Type | File Extension | Description |
|---|---|---|
| Device | .device | A device file recognized by the kernel. |
| Mount | .mount | A file system mount point. |
| Service | .service | A service on the system, including instructions for starting, restarting, and stopping the service. |
| Socket | .socket | A network socket associated with a service. |
| Swap | .swap | A swap device or a swap file. |
| Target | .target | It replaces sysV init run levels that control system boot. |
| Timer | .timer | A systemd timer. |
Types of Daemons
There are 3 types of daemons:
- services
- sockets
- paths
To see the system’s processes in each:
systemctl
systemctl list-units --type service
systemctl list-units --type=service
systemctl list-units --type=socket --state=LOAD
systemctl list-units --type=path --all
systemctl list-unit-files
e.g.
systemctl
Also check out:
systemctl list-unit-files