Comment # 17 on bug 997641 from Thomas Blume

(In reply to Adrian Schr�ter from comment #16)
> JFYI, I have it installed, but according to "systemctl status multipathd" it
> was disabled.

That doesn't really matter in your case.
The multipath device was already set up in the initrd and a path check for a
local disk is redundant anyway.
The problem is apparently that /dev/disk/by-uuid didn't point to the multipath
device at installation time.
I guess this is a race condition, because I couldn't reproduce in my local vm.
bug#986734 shows pretty similar symptoms.
If you still can reproduce the issue, it would be good if you can test wheter
bug 986734 comment#166 fixes it.