RHEL6.3 beta release note ● Thin-provisioning and scalable snapshot capabilities ● The dm-thinp targets, thin and thin-pool, provide a device mapper device with thin- provisioning and scalable snapshot capabilities. This feature is available as a Technology Preview.
LVM support for (non-clustered) thinp snapshots ● A new implementation of LVM copy-on-write (cow) snapshots is available in Red Hat Enterprise Linux 6.3 as a Technology Preview. The main advantage of this implementation, compared to the previous implementation of snapshots, is that it allows many virtual devices to be stored on the same data volume. This implementation also provides support for arbitrary depth of recursive snapshots (snapshots of snapshots of snapshots …).