CentOS virt - Feb 2014 - documentation of snapshots

I am looking for documentation on handling snapshots.  The main
tasks are:

  1.  Create a snapshot

  2.  Roll back a snapshot

  3.  Merge the snapshot into the base to start the cycle over.

Currently I've done steps 1 and 2 into a single qcow2 image.

I'm running a relatively old version of libvirtd on CentOS 5,
libvirt-0.8.2-29.el5_9.1.

Thanks.

Bill
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