- 3.7.1 Displaying the Default and Active System-State Targets
- 3.7.2 Changing the Default and Active System-State Targets
- 3.7.3 Shutting Down, Suspending, or Rebooting the System
- 3.7.4 Starting and Stopping Services
- 3.7.5 Enabling and Disabling Services
- 3.7.6 Displaying the Status of Services
- 3.7.7 Controlling Access to System Resources
- 3.7.8 Modifying systemd Configuration Files
- 3.7.9 Running systemctl on a Remote System
systemd defines system-state targets allow you
to start a system with only the services that are required for a
specific purpose. For example, a server can run more efficiently
with multi-user.target, because it does not run
the X Window System at that run level. It is best to perform
diagnostics, backups, and upgrades with
rescue.target when only root
can use the system. Each run level defines the services that
systemd stops or starts. For example,
systemd starts network services for
multi-user.target and the X Window System for
graphical.target, whereas it stops both of
these services for rescue.target.
Table 3.1, “System-State Targets and Equivalent Run-Level Targets” shows the commonly-used system-state targets and their equivalent run-level targets, where compatibility with Oracle Linux 6 run levels is required.
Table 3.1 System-State Targets and Equivalent Run-Level Targets
System-State Targets | Equivalent Run-Level Targets | Description |
|---|---|---|
|
| Set up a multi-user system with networking and display manager. |
|
| Set up a non-graphical multi-user system with networking. |
|
| Shut down and power off the system. |
|
| Shut down and reboot the system. |
|
| Set up a rescue shell. |
The runlevel* targets are implemented as
symbolic links.
The nearest equivalent systemd target to the
Oracle Linux 6 run levels 2, 3, and 4 is
multi-user.target.
For more information, see the systemd.target(5)
manual page.