On Fri, Oct 26, 2018 at 10:07 PM Markus Stockhausen <stockhausen(a)collogia.de&gt; wrote: Yes, this is expected. Vdsm is monitoring volume size every 60 seconds, based on this configuration: https://github.com/oVirt/vdsm/blob/cbdbee979f0bfc7a7dd447af0d69c5aa9e0f8b... The monitoring is needed to update engine about disk actual size when using thin provisioning. - With block storage, when vdsm detect that a disk is too full, it will extend the disk with help of the SPM host. - With sparse disks on file storage, the disk actual size will grow as the VM writes more data to the disk. Engine show the actual disk size based on the size reported by vdsm, using data collected by these getVolumeSize calls. This check can probably optimized to run only on file based thin provisioned disks instead of any disk. Please file a bug to optimize this is you think it is an issue. Nir