Hello, I'm on oVirt 3.2.3-1 on a Fedora 18 all-in-one test server. I have a Windows XP VM that has a disk in qcow2 format and has a snapshot on it. When I delete the snapshot I see, from the commands intercepted, that the final effect is to have a raw disk (aka preallocated) .... is this correct and always true? Does this mean that even if I create a VM with thin provisioned disks, as soon as I take at least one snapshot and I then delete it I only have raw disks? Or am I missing anything? This what I observed: as soon as I launch delete snapshot operation: raw format of new disk vdsm 30805 1732 6 13:24 ? 00:00:00 /usr/bin/dd if=/dev/zero of=/rhev/data-center/65c9777e-23f1-4f04-8cea-e7c8871dc88b/0a8035e6-e41d-40ff-a154-e0a374f264b2/images/75c54716-5222-4ad6-91f2-8b312eacc4b4/d4fa7785-8a89-4d13-9082-52556ab0b326_MERGE bs=1048576 seek=0 skip=0 conv=notrunc count=11264 oflag=direct after about 5 minutes: convert from qemu format to raw format vdsm 31287 1732 7 13:29 ? 00:00:08 /usr/bin/qemu-img convert -t none -f qcow2 /rhev/data-center/65c9777e-23f1-4f04-8cea-e7c8871dc88b/0a8035e6-e41d-40ff-a154-e0a374f264b2/images/75c54716-5222-4ad6-91f2-8b312eacc4b4/d4fa7785-8a89-4d13-9082-52556ab0b326 -O raw /rhev/data-center/65c9777e-23f1-4f04-8cea-e7c8871dc88b/0a8035e6-e41d-40ff-a154-e0a374f264b2/images/75c54716-5222-4ad6-91f2-8b312eacc4b4/d4fa7785-8a89-4d13-9082-52556ab0b326_MERGE at the end probably there is a rename of the disk file and qemu-img info /rhev/data-center/65c9777e-23f1-4f04-8cea-e7c8871dc88b/0a8035e6-e41d-40ff-a154-e0a374f264b2/images/75c54716-5222-4ad6-91f2-8b312eacc4b4/d4fa7785-8a89-4d13-9082-52556ab0b326 image: /rhev/data-center/65c9777e-23f1-4f04-8cea-e7c8871dc88b/0a8035e6-e41d-40ff-a154-e0a374f264b2/images/75c54716-5222-4ad6-91f2-8b312eacc4b4/d4fa7785-8a89-4d13-9082-52556ab0b326 file format: raw virtual size: 11G (11811160064 bytes) disk size: 9.5G # ll /rhev/data-center/65c9777e-23f1-4f04-8cea-e7c8871dc88b/0a8035e6-e41d-40ff-a154-e0a374f264b2/images/75c54716-5222-4ad6-91f2-8b312eacc4b4/ total 9995476 -rw-rw----. 1 vdsm kvm 1048576 Nov 16 12:09 6ac73ee2-6419-43a4-91e7-7d4ef2026943_MERGE.lease -rw-rw----. 1 vdsm kvm 11811160064 Nov 16 13:32 d4fa7785-8a89-4d13-9082-52556ab0b326 -rw-rw----. 1 vdsm kvm 1048576 Mar 23 2013 d4fa7785-8a89-4d13-9082-52556ab0b326.lease -rw-rw----. 1 vdsm kvm 1048576 Nov 16 13:29 d4fa7785-8a89-4d13-9082-52556ab0b326_MERGE.lease -rw-r--r--. 1 vdsm kvm 274 Nov 16 13:29 d4fa7785-8a89-4d13-9082-52556ab0b326.meta Thanks Gianluca