+++ This bug was initially created as a clone of Bug #153215 +++ I don't know if cloning is the best way to handle this issue, but please see bug #153215 for the details.
if lvm2 can't write to /etc, but you're running a *read-only* lvm2 command, it shouldn't fail. It does - and -An has no effect. The code that creates the backup and archive directories need moving and refining.
Should be fixed in 2.01.08-2.1