I was just wondering, what happens when an LVM snapshot runs out of space? Documentation clearly warns against letting this happen, and I've never even come close, but what would the end result be? Do you just end up with a "filesystem full" scenerio? Can you recover the data that was modified up until the time the snapshot filled? Do you risk filesystem corruption?
I run automated backups in the middle of the night that create snapshots, run backups, then remove the snapshots. I've always feared the "lvremove --force ..." might somehow fail and leave a snapshot active. For now I just make really big snapshots (bigger than the filesystem itself), since I have the disk space to allow this.
Another question for you LVM users - do you snapshot before backing up, or just backup a live filesystem? Generally I use rsync or tar on snapshots. If I want to do a dd I boot Knoppix first. Has anybody tried unionfs for snapshotting non-LVM filesystems? Am I the only one so obsessed about not backing up from a live filesystem???!!!