[linux-lvm] Help! snapshot apparenly trashed LVM

[ross at biostat.ucsf.edu]

I did some expanding and shrinking of my volumes and then attempted to
take a snapshot.  I got an error message that started "Invalid LV in
extent map".  I now see that message when I do lvscan or pvscan as well.

This looks very bad, and seems to be the same situation as described here:
http://weblog.pell.portland.or.us/~orc/2008/02/20/000/index.html

Despite these warnings, I *seem* to be able to use my volumes.  However, I
have stopped doing anything on the system to try to prevent corruption.

First, is it safe to continue to use the system?

Second, what can I do to diagnose or recover?

I'm running a stock Debian 2.6.24 kernel with a single SCSI disk.  Some of
its partitions are dedicated to an LVM group, out of which most of my
partitions are carved.  The LVM groups were originally created under EVMS
with a 2.4 kernel.  I converted them to straight LVM months ago.

Thanks.
Ross Boylan