Hi, In my lab I'm using OLVM ( I know ... it's not original oVirt but it is based on it ). I was using 4.4.10, and after upgrade to 4.5.4 I'm no longer able to create shared disks, on any storage domain (nfs or fc). When I was on previous release I was able to create and use shared disks (required for cluster systems), but after upgrade when I try to create shared disk (preallocated) I'm getting an error saying : Error while executing action: Cannot add Virtual Disk. Disk's volume format is not supported for shareable disk. In engine log I can see only this : 2024-03-31 20:04:28,997+02 WARN [org.ovirt.engine.core.bll.storage.disk.AddDiskCommand] (default task-37) [b8bc1831-260a-4253-b6fe-e0c81a6f81b6] Validation of action 'AddDisk' failed for user admin@internal-authz. Reasons: VAR__ACTION__ADD,VAR__TYPE__DISK,SHAREABLE_DISK_IS_NOT_SUPPORTED_BY_VOLUME_FORMAT Does anyone have idea what could be the reason or how to solve this? Thanks in advance and best regards Igor