systemd-update-done.service, systemd-update-done — Mark /etc
and /var
fully updated
systemd-update-done.service
/usr/lib/systemd/systemd-update-done
systemd-update-done.service
is a service that is invoked as part of the first boot
after the vendor operating system resources in
/usr
have been updated. This is
useful to implement offline updates of
/usr
which might requires updates
to /etc
or
/var
on the following boot.
systemd-update-done.service
updates the file modification time (mtime) of the
stamp files /etc/.updated
and
/var/.updated
to the modification
time of the /usr
directory,
unless the stamp files are already newer.
Services that shall run after offline upgrades
of /usr
should order themselves
before
systemd-update-done.service
, and
use the ConditionNeedsUpdate=
(see
systemd.unit(5))
condition to make sure to run when
/etc
or /var
are older than /usr
according to
the modification times of the files described
above. This requires that updates to
/usr
are always followed by an
update of the modification time of
/usr
, for example by invoking
touch(1)
on it.