after upgrading to oVirt 4.1 and setting cluster/datacenter to version 4, new images and snapshots should be created in qcow2 v3 format, based on bugzilla included in release notes:

Correct?

What about existing disks? Is there any way to convert?

What in case I have an old disk, I create a snapshot in 4.1 and then delete the snapshot? Will the live merged disk be in v3 format or v2?

Thanks,

Gianluca