Cheatsheet Pages / systemd Cheatsheet
How to find and clear failed systemd units — systemctl --failed, reset-failed
Failed units are piling up in the list — find them, fix the cause, then clear the failure state.
Most management commands need sudo, and systemctl only works on a system actually booted with systemd — inside containers it fails with “System has not been booted with systemd as init system”. Every command was checked against systemd 255, and the example units pass systemd-analyze verify.
systemctl --failed # list units in failed state (same as list-units --state=failed)
systemctl status <the-unit> # then read WHY it failed here, and in journalctl -u
sudo systemctl reset-failed nginx # clear the failed state (all units, if you name none)
# reset-failed only clears the flag — fix the cause first, or it just fails again