journalctl - remove logs of a specific unit

Question

With journalctl, it is possible to remove the old logs, by specifying either the maximum disk space they can use, or the maximum age they can have, or the maximum number of separate journal files (using the options --vacuum-size, --vacuum-time or --vacuum-files).

Is there a way to restrain this deletion to a specific systemd unit ?

journalctl -u <unit> --vacuum-time=2d seems not to work as desired: according to the documentation, -u only works when displaying logs.

Answer 1

The self maintenance method is to vacuum the logs by size or time.

Retain only the past two days:

journalctl --vacuum-time=2d

Retain only the past 500 MB:

journalctl --vacuum-size=500M

Source: https://unix.stackexchange.com/questions/139513/how-to-clear-journalctl