I've done a lot with LVM in the past, but up until now had never really played around with LVM snapshots. I recently used LVM snapshots to implement a "hot backup" of my LAMP stack running this blog. I quote "hot backup" because, while mysql is indeed running, I do have to place a read lock on all tables for a second or two. You don't need to do this if you're using Innodb, but you do if you use the MyISAM engine (which Drupal does by default).
