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Check systemd-units-failed

Overview

Checks for failed systemd units by running systemctl --state=failed. Reports any unit that is in a failed active state or failed sub state.

When no unit is currently failed, the plugin reads the current boot's journal for the most recent system unit-failed event and appends it to the output, so the admin sees how long the host has been clean since the last reboot and which unit last broke.

Data Collection:

  • Executes systemctl --state=failed --no-pager --no-legend
  • When everything is OK, additionally runs journalctl --output=short-unix --boot=0 _PID=1 --grep="Failed with result" and picks the last matching line client-side, to read the most recent system-scope unit-failed event of the current boot. Scoping to --boot=0 keeps the call fast regardless of total journal size. If journalctl is unavailable, returns nothing, or its entry cannot be parsed, the suffix is silently omitted
  • Units can be excluded from the check via --ignore, which supports glob patterns according to Python's fnmatch module (e.g. --ignore "sshd@*.service")

Fact Sheet

Fact Value
Check Plugin Download https://github.com/Linuxfabrik/monitoring-plugins/tree/main/check-plugins/systemd-units-failed
Nagios/Icinga Check Name check_systemd_units_failed
Check Interval Recommendation Every minute
Can be called without parameters Yes
Runs on Linux
Compiled for Windows No

Help

usage: systemd-units-failed [-h] [-V] [--always-ok] [--ignore IGNORE]
                            [--test TEST]

Checks for failed systemd units. Alerts when any unit is in a failed state.
Specific units can be excluded from the check via --ignore with regular
expressions. When no unit is currently failed, reports the most recent system
unit-failed event from the current boot's journal so operators see at a glance
how long the host has been clean since the last reboot.

options:
  -h, --help       show this help message and exit
  -V, --version    show program's version number and exit
  --always-ok      Always returns OK.
  --ignore IGNORE  Unit name to exclude from the check. Can be specified
                   multiple times. Supports glob patterns according to
                   https://docs.python.org/3/library/fnmatch.html. Example:
                   `--ignore "dhcpd.service"`. Default: []
  --test TEST      For unit tests. Needs "path-to-stdout-file,path-to-stderr-
                   file,expected-retc".

Usage Examples

./systemd-units-failed --ignore=openipmi.service --ignore=dhcpd.service

./systemd-units-failed --ignore=sshd@*.service

Output (something is failing):

1 failed unit: ipmievd.service

unit            ! load   ! active ! sub    ! description
----------------+--------+--------+--------+----------------
ipmievd.service ! loaded ! failed ! failed ! Ipmievd Daemon

Output (currently clean, with last failure surfaced from the journal):

Everything is ok. Last failed: `ipmievd.service` with message "Failed with result 'exit-code'" at 2026-04-30 12:01:53 (1W 2D ago)

States

  • OK if no units are in a failed state.
  • WARN if at least one unit has a failed active state or failed sub state.
  • --always-ok suppresses all alerts and always returns OK.

Perfdata / Metrics

Name Type Description
systemd-units-failed Number Number of failed units

Troubleshooting

If you cannot fix the underlying issue and simply want to reset the status of a failed unit:

systemctl reset-failed ipmievd.service

Credits, License