SYSTEMD-MACHINE-ID-COMMsystemd-machine-id-SYSTEMD-MACHINE-ID-COMMIT.SERVICE(8)
NAME
systemd-machine-id-commit.service - Commit transient machine-id to disk
SYNOPSIS
systemd-machine-id-commit.service
/usr/lib/systemd/systemd-machine-id-commit
DESCRIPTION
systemd-machine-id-commit.service is a service responsible for
committing any transient /etc/machine-id file to a writable file
system. See machine-id(5) for more information about this file.
This service is started shortly after local-fs.target if
/etc/machine-id is an independent mount point (probably a tmpfs one)
and /etc is writable. systemd-machine-id-commit will then write
current machine ID to disk and unmount the transient /etc/machine-id
file in a race-free manner to ensure that 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. The main use case for
that service is /etc/machine-id being an empty file at boot and initrd
chaining to systemd giving it a read only file system that will be
turned read-write later during the boot process.
There is no consequence if that service fails other than a newer
machine-id will be generated during next system boot.
SEE ALSO
systemd(1), systemd-machine-id-commit(1), systemd-machine-id-setup(1),
machine-id(5), systemd-firstboot(1)
systemd 219 SYSTEMD-MACHINE-ID-COMMIT.SERVICE(8)