systemd offline-update functionality

Hello,

I would like to use systemd’s “offline-update” functionality for a firmware-updating service.  After playing with it a bit, I have a couple questions that I was hoping someone could help me with:  

1. Per documentation at https://www.freedesktop.org/software/systemd/man/systemd.offline-updates.html,  “If the system-update.target is successfully reached, i.e. all update services have run, and the /system-update symlink still exists, it will be removed and the machine rebooted as a safety measure.”

I have not observed this behavior in testing; in fact, I cannot find any code in systemd that removes the “/system-update” symlink if the update script fails.  Is this still the expected behavior or is the update script responsible for deleting the symlink?

2. The same documentation page recommends setting “FailureAction = reboot” in case the update script fails to complete.  However, this does not seem to reboot the machine properly (e.g. I don’t see a POST screen + grub as expected).  Using “reboot-force” does seem to have the expected behavior.  What is the difference between these two methods?

Any help would be much appreciated.

Thanks,

~ Michael

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Michael Zhivich

Linux Kernel Team

mzhivich@xxxxxxxxxx

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