I am trying to understand how snapshots work but I guess I am stuck on what consitutes a changed block. A block that written to, even with the same data as before. Or block what actually has modified data. What method does LVM use to decide whether block has been changed or not. Thanks _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/