Created attachment 1676865 [details]
logs

Description of problem:
Creation of live snapshot of VM wirh RO disk fails with the following errors:

VDSM:
2020-04-07 11:34:30,795+0300 ERROR (virt/209906f8) [virt.vm] (vmId='144b3b7d-768e-4658-ac54-c4e32ff175c6') Unable to take snapshot (snapshot:463)
Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/vdsm/virt/jobs/snapshot.py", line 453, in snapshot
    self._vm.run_dom_snapshot(snapxml, snap_flags)
  File "/usr/lib/python3.6/site-packages/vdsm/virt/vm.py", line 5585, in run_dom_snapshot
    self._dom.snapshotCreateXML(snapxml, snap_flags)
  File "/usr/lib/python3.6/site-packages/vdsm/virt/virdomain.py", line 101, in f
    ret = attr(*args, **kwargs)
  File "/usr/lib/python3.6/site-packages/vdsm/common/libvirtconnection.py", line 131, in wrapper
    ret = f(*args, **kwargs)
  File "/usr/lib/python3.6/site-packages/vdsm/common/function.py", line 94, in wrapper
    return func(inst, *args, **kwargs)
  File "/usr/lib64/python3.6/site-packages/libvirt.py", line 2800, in snapshotCreateXML
    if ret is None:raise libvirtError('virDomainSnapshotCreateXML() failed', dom=self)
libvirt.libvirtError: unsupported configuration: external snapshot for readonly disk sda is not supported

Errors in engine log appears after ~30 min:
2020-04-07 12:04:35,307+03 ERROR [org.ovirt.engine.core.bll.snapshots.CreateLiveSnapshotForVmCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-86) [42badbc4-77db-4aa9-b7a5-4513b8e8cf15] Ending command 'org.ovirt.engine.core.bll.snapshots.CreateLiveSnapshotForVmCommand' with failure.
2020-04-07 12:04:37,411+03 ERROR [org.ovirt.engine.core.bll.snapshots.CreateSnapshotForVmCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-35) [42badbc4-77db-4aa9-b7a5-4513b8e8cf15] Ending command 'org.ovirt.engine.core.bll.snapshots.CreateSnapshotForVmCommand' with failure.
2020-04-07 12:04:37,522+03 ERROR [org.ovirt.engine.core.bll.snapshots.CreateSnapshotDiskCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-35) [42badbc4-77db-4aa9-b7a5-4513b8e8cf15] Ending command 'org.ovirt.engine.core.bll.snapshots.CreateSnapshotDiskCommand' with failure.
2020-04-07 12:04:37,534+03 ERROR [org.ovirt.engine.core.bll.snapshots.CreateSnapshotCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-35) [42badbc4-77db-4aa9-b7a5-4513b8e8cf15] Ending command 'org.ovirt.engine.core.bll.snapshots.CreateSnapshotCommand' with failure.
2020-04-07 12:04:37,554+03 ERROR [org.ovirt.engine.core.vdsbroker.vdsbroker.HSMRevertTaskVDSCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-35) [42badbc4-77db-4aa9-b7a5-4513b8e8cf15] Trying to revert unknown task '2e8c401f-f6cc-423c-9e98-c23eebf3e21b'
2020-04-07 12:04:38,252+03 ERROR [org.ovirt.engine.core.bll.snapshots.CreateSnapshotCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-35) [42badbc4-77db-4aa9-b7a5-4513b8e8cf15] Ending command 'org.ovirt.engine.core.bll.snapshots.CreateSnapshotCommand' with failure.
2020-04-07 12:04:38,270+03 ERROR [org.ovirt.engine.core.vdsbroker.vdsbroker.HSMRevertTaskVDSCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-35) [42badbc4-77db-4aa9-b7a5-4513b8e8cf15] Trying to revert unknown task '2ec03ff8-985a-47c1-9a18-0dc53ae9281e'
2020-04-07 12:04:38,731+03 ERROR [org.ovirt.engine.core.bll.storage.disk.AddDiskCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-35) [42badbc4-77db-4aa9-b7a5-4513b8e8cf15] Ending command 'org.ovirt.engine.core.bll.storage.disk.AddDiskCommand' with failure.
2020-04-07 12:04:38,743+03 ERROR [org.ovirt.engine.core.bll.storage.disk.image.AddImageFromScratchCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-35) [42badbc4-77db-4aa9-b7a5-4513b8e8cf15] Ending command 'org.ovirt.engine.core.bll.storage.disk.image.AddImageFromScratchCommand' with failure.
2020-04-07 12:04:38,764+03 ERROR [org.ovirt.engine.core.vdsbroker.vdsbroker.HSMRevertTaskVDSCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-35) [42badbc4-77db-4aa9-b7a5-4513b8e8cf15] Trying to revert unknown task '0f8297ed-6637-4ddb-a8e4-d8e101a18ee4'
2020-04-07 12:04:38,800+03 ERROR [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-35) [] EVENT_ID: USER_ADD_DISK_FINISHED_FAILURE(2,022), Add-Disk operation failed to complete.
2020-04-07 12:04:38,813+03 ERROR [org.ovirt.engine.core.bll.storage.disk.image.AddImageFromScratchCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-35) [42badbc4-77db-4aa9-b7a5-4513b8e8cf15] Ending command 'org.ovirt.engine.core.bll.storage.disk.image.AddImageFromScratchCommand' with failure.
2020-04-07 12:04:38,844+03 ERROR [org.ovirt.engine.core.vdsbroker.vdsbroker.HSMRevertTaskVDSCommand] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-35) [42badbc4-77db-4aa9-b7a5-4513b8e8cf15] Trying to revert unknown task 'c4bf39da-d00b-48a0-bb40-3fd999a49805'
2020-04-07 12:04:38,878+03 ERROR [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-35) [] EVENT_ID: USER_ADD_DISK_FINISHED_FAILURE(2,022), Add-Disk operation failed to complete.
2020-04-07 12:04:38,910+03 ERROR [org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector] (EE-ManagedScheduledExecutorService-engineScheduledThreadPool-Thread-35) [] EVENT_ID: USER_CREATE_SNAPSHOT_FINISHED_FAILURE(69), Failed to complete snapshot 's1' creation for VM 'golden_env_mixed_virtio_2_0'.


Version-Release number of selected component (if applicable):
vdsm-4.40.11-1.el8ev.x86_64
engine-4.4.0-0.31.master.el8ev

How reproducible:
100%

Steps to Reproduce:
1. Create VM with disk
2. Attach RO to the VM
3. Run VM
4. Try to take live snapshot

Actual results:
Operation fails, error appears on the UI after ~30 min.

Expected results:
Operation should succeed

Additional info:
Logs are attached.