Provided by: systemd_229-4ubuntu21.31_amd64 bug


       systemd-machine-id-commit.service - Commit a transient machine ID to disk




       systemd-machine-id-commit.service is an early boot service responsible for committing
       transient /etc/machine-id files to a writable disk file system. See machine-id(5) for more
       information about machine IDs.

       This service is started after in case /etc/machine-id is a mount point of
       its own (usually from a memory file system such as "tmpfs") and /etc is writable. The
       service will invoke systemd-machine-id-setup --commit, which writes the current transient
       machine ID to disk and unmount the /etc/machine-id file in a race-free manner to ensure
       that file is always valid and accessible for other processes. See systemd-machine-id-
       setup(1) for details.

       The main use case of this service are systems where /etc/machine-id is read-only and
       initially not initialized. In this case, the system manager will generate a transient
       machine ID file on a memory file system, and mount it over /etc/machine-id, during the
       early boot phase. This service is then invoked in a later boot phase, as soon as /etc has
       been remounted writable and the ID may thus be committed to disk to make it permanent.


       systemd(1), systemd-machine-id-setup(1), machine-id(5), systemd-firstboot(1)