Hi list,
I forgot to check "Discard after Delete" when creating a new volume. Is there a way (other than to empty the volume) to reclaim free blocks.
You can enable discard after delete by puting the storage domain to maintenace and modifying the domain advanced options.
If the storage supports discard, and you did not select wipe after delete storage domain option, and you use virtio-scsi interface, you can use "fstrim" in the guest to free unused space.
Using fstrim does not reduce logical volume allocation size, only block in the underlying storage.
Nir