[ovirt-users] is disk reduce command while VM is active after snapshot deletion save?

When creating a snapshot, the volume gets two lv extents (2GB) . But after deleting the snapshot, the extents are kept and with every Snapshot creation the volume size increases. This is really annoying, especially when using snapshot for nightly backup. we are using oVirt 4.3.10 and we can't upgrade to 4.4 I have read that to shrink the volume the disk reduce command is what helps here, but the rest api documentation says, that this is only applicable while vm is not running. crazy as i am, i have called the reduce command while the vm was running, and it seemed to work. the volume has shrunk and the vm didn't crash. But is it save to do so? and why isn't the reduce command is called after deletion of a snapshot?