Comment # 30 on bug 1155170 from Michael Hirmke

(In reply to Franck Bui from comment #27)
> (In reply to Michael Hirmke from comment #23)
> > 1. "Boot device is still in use" on a reboot - the reason for this seems to
> > be an installation via zypper.
> 
> So regarding this issue, the problem is that systemd shouldn't attempt to
> detach the root device at all since it's going to be used until the very
> last end, when the system will switch back to initrd.
> 
> Since this problem is not specific to openSUSE, I opened an issue against
> upstream and it will be tracked at
> https://github.com/systemd/systemd/issues/14224 from now on.

Thx a lot!

> 
> That said the warning should be harmless and the root device should be
> unmounted and detached by dracut (Thomas, please correct me if I'm wrong).

At least there is no message, that root has been unmounted correctly.
Instead you can see in the log, that the last fuser output shows lots of
processes blockkung the root filesystem. Instead you can see messages like

systemd-cryptsetup@root.service: Unit entered failed state.

Remember: root is encrypted!