Comment # 27 on bug 1080485 from Neil Rickert

Created attachment 780445 [details]
Screenshot showing the error messages

Something changed with snapshot 20180818

I am now seeing these errors on every shutdown.  This is with a KVM virtual
machine, where I previously never could produced the problem.  And I do have
"plymouth.enable=0".

Responding to c#26
>My guess would be that disabling plymouth only hides the messages.

I disagree with that.  My guess is that plymouth is using something from the
root file system, perhaps a dynamic ".so" library.

But now it is happening even with plymouth disabled.  So some other component
is now using something from the root file system.

NOTE: I did check.  I booted to rescue mode (with installer DVD), and an "fsck"
on all file systems showed them to be clean.

My personal opinion:  this is all a mistake.  The system should not try to
disassemble device mapper setup.  It should just reset the system and abandon
the current setup.  What makes the device mapper setup is all in volatile
storage.  So it goes away on reset.  No need to tear it down.  What's important
is that everything has been remounted as read-only (or has been unmounted).