February 28, 2023
I was faffing about with the
systemd-resolved service today and wanted to increase the verbosity of its logging, which I did through
systemctl edit systemd-resolved. That opened up an editor where I just added the following:
And restarted the service. Now though I didn’t want to go spelunking for the override file myself (I know it lives under
/etc/systemd/system, but still) and go through the rigamarole of reverting it myself. Turns out one can just use the
systemctl revert command:
$ systemctl revert systemd-resolved.service
systemctl restart systemd-resolved and that’s it!
This command is useful if you know you’ve ever modified a unit file at some other point in time and just want to go back to how it was originally. From its man page (emphasis mine):
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Revert one or more unit files to their vendor versions. This command removes drop-in configuration files that modify the specified units, as well as any user-configured unit file that overrides a matching vendor supplied unit file. Specifically, for a unit “foo.service” the matching directories “foo.service.d/” with all their contained files are removed, both below the persistent and runtime configuration directories (i.e. below /etc/systemd/system and /run/systemd/system); if the unit file has a vendor-supplied version (i.e. a unit file located below /usr/) any matching persistent or runtime unit file that overrides it is removed, too. Note that if a unit file has no vendor-supplied version (i.e. is only defined below /etc/systemd/system or /run/systemd/system, but not in a unit file stored below /usr/), then it is not removed. Also, if a unit is masked, it is unmasked.
Effectively, this command may be used to undo all changes made with
systemctl maskand puts the original unit file with its settings back in effect.