SYSTEMD-MACHINE-ID-COMMsystemd-machine-id-SYSTEMD-MACHINE-ID-COMMIT.SERVICE(8)
NAME
systemd-machine-id-commit.service - Commit a transient machine ID to
disk
SYNOPSIS
systemd-machine-id-commit.service
DESCRIPTION
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 local-fs.target 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.
SEE ALSO
systemd(1), systemd-machine-id-setup(1), machine-id(5), systemd-
firstboot(1)
systemd 245 SYSTEMD-MACHINE-ID-COMMIT.SERVICE(8)