Today I learned that
journald will no longer start when
/etc/machine-id is removed.
journald takes care of the logging in a modern Linux system following the freedesktop standards. The
machine-id is a unique ID for each system that the freedesktop standard considers important to differentiate the machine. It’s usually created on first boot up by
systemd-machine-id-setup and will stay the same throughout the lifetime of the system.
I came across this while working on a RHEL system image and figuring out some software dependencies. To make images working properly I decided to delete the
machine-id file. Later noticing that logs were no longer available due to
journald refusing to start. You will notice that
journalctl -xe will show you the following line at the end “
systemd-journal: Journal stopped”, which is
journald exiting after
dracut hands over the system.