On 10/13/2014 04:39 AM, Sijo Jose wrote: The snapshots are independent. Deleting one does not invalidate the other. In more detail, internal snapshots are implemented by ref-counting in the qcow2 file format. Prior to a snapshot, all allocated clusters have a ref-count of 1. When you create a snapshot, all current clusters have their ref-count incremented. When you write to a cluster, if the ref-count is larger than 1, it does a copy-on-write operation to put the write in a new cluster (the COW part of qcow2), and decrements the ref-count of the old cluster. When reverting to a snapshot, you are just changing which set of clusters is current. When deleting a snapshot, you decrement the ref-count of all clusters pointed to by the snapshot, possibly freeing memory for clusters that drop to 0 ref-count. -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org