# phpman > info > systemd-machine-id-commit.service

[SYSTEMD-MACHINE-ID-COMMsystemd-machine-id-SYSTEMD-MACHINE-ID-COMMIT.SERVICE(8)](https://www.chedong.com/phpMan.php/man/SYSTEMD-MACHINE-ID-COMMsystemd-machine-id-SYSTEMD-MACHINE-ID-COMMIT.SERVICE/8/markdown)

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)](https://www.chedong.com/phpMan.php/man/machine-id/5/markdown) 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)](https://www.chedong.com/phpMan.php/man/systemd-machine-id-setup/1/markdown) 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)](https://www.chedong.com/phpMan.php/man/systemd/1/markdown), [systemd-machine-id-setup(1)](https://www.chedong.com/phpMan.php/man/systemd-machine-id-setup/1/markdown), [machine-id(5)](https://www.chedong.com/phpMan.php/man/machine-id/5/markdown), systemd-
       [firstboot(1)](https://www.chedong.com/phpMan.php/man/firstboot/1/markdown)

systemd 249                               [SYSTEMD-MACHINE-ID-COMMIT.SERVICE(8)](https://www.chedong.com/phpMan.php/man/SYSTEMD-MACHINE-ID-COMMIT.SERVICE/8/markdown)