Some LVM tutorials seem to claim that one take a snapshot of a logical volume (LV), then backup the snapshot using another tool, then remove the snapshot. When the unspeakable happens, the user can restore their LV to the state it was during the backup.
But how can this be? LVM snapshots are "copy on write"; they record changes to the state, not the state itself. If the snapshot is removed and changes are then made to the LV's state, these changes are not recorded; thus, the backup contains an incomplete record of changes to the LV during the attempted merge. So how can one expect their LV to be restored to the state it was during the backup?