systemd-machine-id-commit — Commit transient machine ID to /etc/machine-id
systemd-machine-id-commit
systemd-machine-id-commit may be used to
write on disk any transient machine ID mounted as a temporary file
system in /etc/machine-id at boot time. See
machine-id(5)
for more information about this file.
This tool will execute no operation if
/etc/machine-id doesn't contain any valid
machine ID, isn't mounted as an independent temporary file system,
of /etc is read-only. If those conditions are
met, it will then write current machine ID to disk and unmount the
transient /etc/machine-id file in a race-free
manner to ensure that this file is always valid for other
processes.
Note that the traditional way to initialize the machine ID
in /etc/machine-id is to use
systemd-machine-id-setup by system installer
tools. You can also use
systemd-firstboot(1)
to initialize the machine ID on mounted (but not booted) system
images.