Version: oVirt engine: 4.4.7.7-1.el8 oVirt node: 4.4.7 Steps of reproducing the problem: After a series of regular/successful backup tests by using CBT+imageio API, at one of the backup session beginning, when trying to obtain the VM config and snapshot list (obtain snapshot list can determine the VM disk is in RAW or QCOW2 format) by using `GET vms/<vm-id>/snapshots`, the below error is received. <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <fault> <detail>duplicate key acf1edaa-e950-4c4f-94df-1bd6b3da49c1 (attempted merging values org.ovirt.engine.core.common.businessentities.storage.diskimage@5103046c and org.ovirt.engine.core.common.businessentities.storage.diskimage@d973046c)</detail> <reason>Operation Failed</reason> </fault> After this on the oVirt engine web console, we saw the VM which should only have 1 disk is now showing 2 disks, the disk status always in Finalizing state. It's been more than 30 hours but the VM still got duplicated disks and still showing Finalizing, there's no way to modify the virtual disk or take snapshots for the VM.