systemd run states

[Trevor]

systemd does not use runlevels.  What does it use instead?

[veera-rhls]

Systemd is the new way to start up your computer. It doesn't use the old number codes (called runlevels) to decide what to do. Instead, it uses names called "targets" like "Multi-User" or "Graphical") to describe what the computer should be doing and it automatically starts all the things it needs to reach that goal.

[Chetan_Tiwary_]

@Trevor Thanks for reaching out !

Systemd uses targets instead of traditional runlevels to define the system's state, but with far more flexibility and precision.

The common ones line up like this: poweroff.target is your runlevel 0 (shutdown), rescue.target matches runlevel 1 (single-user mode), multi-user.target takes runlevel 3's place for console access, graphical.target is runlevel 5 for GUI desktops, and reboot.target handles runlevel 6 reboots. There's also default.target, just a symlink to whatever your system boots into by default.

You can check it with #systemctl get-default or switch it permanently using #systemctl set-default graphical.target. For a quick temporary change, #sudo systemctl isolate multi-user.target does the trick.

What makes targets better than runlevels?

They are named and descriptive instead of cryptic numbers, so you can create custom ones and build dependency trees for complex service relationships. Plus, systemd starts services in parallel for much faster boots, unlike the old SysV init's sequential slog.

https://www.freedesktop.org/software/systemd/man/latest/systemd.target.html 

https://www.freedesktop.org/software/systemd/man/latest/systemd.special.html#