Sorry I was trying to open a new thread for this issue, but it seems I failed to submit. Here let me explain how the issue is reproduced.

It’s a regular backup by using CBT+imageip API, after a series of successful backup, at one of the backup session beginning, when we try to obtain the VM config and the snapshot list (obtain snapshot list can determine the VM virtual disk format is RAW or QCOW2) by using `GET vms/<vm-id>/snapshots`, but get the following error.

<?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 oVirt engine web console, the VM show 2 disks (actually it only has 1) , and the disk status always showing “Finalizing”, it’s been more than 30 hours now, and during this, cannot modify VM disk or take snapshots.

Before upgrading oVirt engine to 4.4.7.7-1.el8 this problem happened frequently, after upgrading, the frequency is reduced.

Here I’m adding the engine logs and vdsm logs.
Engine logs: https://drive.google.com/file/d/1T3-EOxYYl3oFZOA9VMMBte5WyBoUO48U/view?usp=sharing
VDSM logs: https://drive.google.com/file/d/1x0B8lGqnKEDrgn666CuN3hqUGwD7fcYv/view?usp=sharing

Thanks & regards!
On 07/29/2021 19:20Nir Soffer<nsoffer@redhat.com> wrote:
On Thu, Jul 29, 2021 at 10:08 AM luwen.zhang <luwen.zhang@vinchin.com> wrote:
The problem occurred yesterday, but we waited for more than 20 hours, still 2 disks and in Finalizing state.

If the image transfer is "finalizing" it means the image transfer is
trying to finalize, but the operation could not complete.

In this phase the disk remains locked, and it should not be possible
to start a new image transfer
(e.g perform another backup).

Engine and vdsm logs should explain why the image transfer is stuck in
the finalizing phase.

Can you add detailed instructions on how to reproduce this issue?