WalterH As promised, I have clone my VM and run the updates again. /usr/lib/tmpfiles.d/journal-nocow.conf is the same as advised above - before and after the failed update.
Journalctl -f yields the following:-
Jan 25 17:00:14 MAILSERVER systemd[1]: /usr/lib/systemd/system/rpc-statd.service:14: PIDFile= references a path below legacy directory /var/run/, updating /var/run/rpc.statd.pid → /run/rpc.statd.pid; please update the unit file accordingly.
Jan 25 17:00:14 MAILSERVER systemd[1]: Reloading.
Jan 25 17:00:14 MAILSERVER systemd[1]: /usr/lib/systemd/system/rpc-statd.service:14: PIDFile= references a path below legacy directory /var/run/, updating /var/run/rpc.statd.pid → /run/rpc.statd.pid; please update the unit file accordingly.
Jan 25 17:00:14 MAILSERVER uwsgi[16139]: stat: cannot statx '/etc/machine-id': No such file or directory
Jan 25 17:00:14 MAILSERVER uwsgi[16139]: Incorrect file mode bits for /etc/machine-id which should be 0444, fixing...
Jan 25 17:00:14 MAILSERVER uwsgi[16139]: chmod: cannot access '/etc/machine-id': No such file or directory
Jan 25 17:00:14 MAILSERVER [RPM][16349]: install systemd-249.17-150400.8.40.1.x86_64: success
Jan 25 17:00:14 MAILSERVER systemd[1]: Reloading.
Jan 25 17:00:15 MAILSERVER systemd[1]: /usr/lib/systemd/system/rpc-statd.service:14: PIDFile= references a path below legacy directory /var/run/, updating /var/run/rpc.statd.pid → /run/rpc.statd.pid; please update the unit file accordingly.
Jan 25 17:00:15 MAILSERVER systemd-journald[566]: Journal stopped
I have actioned the request in this line of the log file,
PIDFile= references a path below legacy directory /var/run/, updating /var/run/rpc.statd.pid → /run/rpc.statd.pid
and rerun the update, as the script does not do this itself even though it reads like out is trying to..
I did not have a /etc/machine-id in my /etc directory, so I created it. I left the permissions at 0644 as it looks like the install script may change it when it has update the file to 0444. I assumed that if I set it to 0444 the script may not be able to mod the file.
I then re-ran the updates of the test VM
I was unable to re-run the updates as the GUI updater just tales me back to the screen the top of this ticket, so I rebooted the VM and it came up OK, with no error in the GUI 'monitoring' logs.
Re-running Updates reporting an issue with REDIS service, but the post update script restarted this with our issue. A further reboot seems to have started without issue and no reported errors.
The file /usr/lib/tmpfiles.d/journal-nocow.conf remains unchanged even after what appears to be a successful update. The script has not changed the permissions on /etc/machine-id from 0644 to 0444 as implied in the original errors.
It looks like the install script might need a little tuning to prevent the above errors for other users.
Mark