Please see this thread: http://asg.web.cmu.edu/archive/message.php?mailbox=archive.info-cyrus&msg=26746
Speaking of which, I think I've found the solution to the snapshot issues. It appears that Sistina distribute a patch in the LVM sources to fix this problem, but Red Hat (at least in version 8) don't include the patch in their kernels. As a result, their kernels support LVM but have problems taking snapshots of volumes containing journalling filesystems.
You can get the patch from the LVM sources at sistina.com (ftp://ftp.sistina.com/pub/LVM/1.0/ ). It's called LVM/1.0.8/PATCHES/linux-$VERSION-VFS-lock.patch in the LVM tarball. I'll be trying it on the server at work once I've tested it on my home machine, but I thought I'd let you folks know now in case it's of use.
Off we go...
Craig Ringer
