According to this one (GlusterFS Storage Domain — oVirt) libgfapi support is disabled by default due to incompatibility with Live Storage Migration. VM can not be migrated to the GlusterFS storage domain.
I guess someone from the devs have to confirm that this is still valid.

Best Regards,Strahil Nikolov

    В четвъртък, 18 юли 2019 г., 11:16:26 ч. Гринуич+3, Christoph Köhler <koehler@luis.uni-hannover.de> написа: 

 Hello,

I try to migrate a disk of a running vm from gluster 3.12.15 to gluster
3.12.15 but it fails. libGfApi set to true by engine-config.

° taking a snapshot first, is working. Then at engine-log:

2019-07-18 09:29:13,932+02 ERROR
[org.ovirt.engine.core.vdsbroker.vdsbroker.VmReplicateDiskStartVDSCommand]
(EE-ManagedThreadFactory-engineScheduled-Thread-84)
[c957e011-37e0-43aa-abe7-9bb633c38c5f] Failed in
'VmReplicateDiskStartVDS' method

2019-07-18 09:29:13,936+02 ERROR
[org.ovirt.engine.core.dal.dbbroker.auditloghandling.AuditLogDirector]
(EE-ManagedThreadFactory-engineScheduled-Thread-84)
[c957e011-37e0-43aa-abe7-9bb633c38c5f] EVENT_ID:
VDS_BROKER_COMMAND_FAILURE(10,802), VDSM ovvirt07 command
VmReplicateDiskStartVDS failed: Drive replication error

2019-07-18 09:29:13,936+02 INFO
[org.ovirt.engine.core.vdsbroker.vdsbroker.VmReplicateDiskStartVDSCommand]
(EE-ManagedThreadFactory-engineScheduled-Thread-84)
[c957e011-37e0-43aa-abe7-9bb633c38c5f] Command
'org.ovirt.engine.core.vdsbroker.vdsbroker.VmReplicateDiskStartVDSCommand'
return value 'StatusOnlyReturn [status=Status [code=55, message=Drive
replication error]]'

2019-07-18 09:29:13,936+02 INFO
[org.ovirt.engine.core.vdsbroker.vdsbroker.VmReplicateDiskStartVDSCommand]
(EE-ManagedThreadFactory-engineScheduled-Thread-84)
[c957e011-37e0-43aa-abe7-9bb633c38c5f] HostName = ovvirt07

2019-07-18 09:29:13,937+02 ERROR
[org.ovirt.engine.core.vdsbroker.vdsbroker.VmReplicateDiskStartVDSCommand]
(EE-ManagedThreadFactory-engineScheduled-Thread-84)
[c957e011-37e0-43aa-abe7-9bb633c38c5f] Command
'VmReplicateDiskStartVDSCommand(HostName = ovvirt07,
VmReplicateDiskParameters:{hostId='3a7bf85c-e92d-4559-908e-5eed2f5608d4',
vmId='3b79d0c0-47e9-47c3-8511-980a8cfe147c',
storagePoolId='00000001-0001-0001-0001-000000000311',
srcStorageDomainId='e54d835a-d8a5-44ae-8e17-fcba1c54e46f',
targetStorageDomainId='4dabb6d6-4be5-458c-811d-6d5e87699640',
imageGroupId='d2964ff9-10f7-4b92-8327-d68f3cfd5b50',
imageId='62656632-8984-4b7e-8be1-fd2547ca0f98'})' execution failed:
VDSGenericException: VDSErrorException: Failed to
VmReplicateDiskStartVDS, error = Drive replication error, code = 55

2019-07-18 09:29:13,937+02 INFO
[org.ovirt.engine.core.vdsbroker.vdsbroker.VmReplicateDiskStartVDSCommand]
(EE-ManagedThreadFactory-engineScheduled-Thread-84)
[c957e011-37e0-43aa-abe7-9bb633c38c5f] FINISH,
VmReplicateDiskStartVDSCommand, return: , log id: 5b2afb0b

2019-07-18 09:29:13,937+02 ERROR
[org.ovirt.engine.core.bll.storage.lsm.LiveMigrateDiskCommand]
(EE-ManagedThreadFactory-engineScheduled-Thread-84)
[c957e011-37e0-43aa-abe7-9bb633c38c5f] Failed VmReplicateDiskStart (Disk
'd2964ff9-10f7-4b92-8327-d68f3cfd5b50' , VM
'3b79d0c0-47e9-47c3-8511-980a8cfe147c')

2019-07-18 09:29:13,938+02 ERROR
[org.ovirt.engine.core.bll.SerialChildCommandsExecutionCallback]
(EE-ManagedThreadFactory-engineScheduled-Thread-84)
[c957e011-37e0-43aa-abe7-9bb633c38c5f] Command 'LiveMigrateDisk' id:
'8174c74c-8ab0-49fa-abfc-44d8b7c691e0' with children
[03672b60-443b-47ba-834c-ac306d7129d0,
562522fc-6691-47fe-93bf-ef2c45e85676] failed when attempting to perform
the next operation, marking as 'ACTIVE'

2019-07-18 09:29:13,938+02 ERROR
[org.ovirt.engine.core.bll.SerialChildCommandsExecutionCallback]
(EE-ManagedThreadFactory-engineScheduled-Thread-84)
[c957e011-37e0-43aa-abe7-9bb633c38c5f] EngineException: Drive
replication error (Failed with error replicaErr and code 55):
org.ovirt.engine.core.common.errors.EngineException: EngineException:
Drive replication error (Failed with error replicaErr and code 55)
        at
org.ovirt.engine.core.bll.storage.lsm.LiveMigrateDiskCommand.replicateDiskStart(LiveMigrateDiskCommand.java:526)
[bll.jar:]
        at
org.ovirt.engine.core.bll.storage.lsm.LiveMigrateDiskCommand.performNextOperation(LiveMigrateDiskCommand.java:233)
[bll.jar:]
        at
org.ovirt.engine.core.bll.SerialChildCommandsExecutionCallback.childCommandsExecutionEnded(SerialChildCommandsExecutionCallback.java:32)
[bll.jar:]
        at
org.ovirt.engine.core.bll.ChildCommandsCallbackBase.doPolling(ChildCommandsCallbackBase.java:77)
[bll.jar:]
        at
org.ovirt.engine.core.bll.tasks.CommandCallbacksPoller.invokeCallbackMethodsImpl(CommandCallbacksPoller.java:175)
[bll.jar:]
        at
org.ovirt.engine.core.bll.tasks.CommandCallbacksPoller.invokeCallbackMethods(CommandCallbacksPoller.java:109)
[bll.jar:]
        at
java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
[rt.jar:1.8.0_212]
        at
java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
[rt.jar:1.8.0_212]
        at
org.glassfish.enterprise.concurrent.internal.ManagedScheduledThreadPoolExecutor$ManagedScheduledFutureTask.access$201(ManagedScheduledThreadPoolExecutor.java:383)
[javax.enterprise.concurrent-1.0.jar:]
        at
org.glassfish.enterprise.concurrent.internal.ManagedScheduledThreadPoolExecutor$ManagedScheduledFutureTask.run(ManagedScheduledThreadPoolExecutor.java:534)
[javax.enterprise.concurrent-1.0.jar:]
        at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
[rt.jar:1.8.0_212]
        at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
[rt.jar:1.8.0_212]
        at java.lang.Thread.run(Thread.java:748) [rt.jar:1.8.0_212]
        at
org.glassfish.enterprise.concurrent.ManagedThreadFactoryImpl$ManagedThread.run(ManagedThreadFactoryImpl.java:250)
[javax.enterprise.concurrent-1.0.jar:]
        at
org.jboss.as.ee.concurrent.service.ElytronManagedThreadFactory$ElytronManagedThread.run(ElytronManagedThreadFactory.java:78)

2019-07-18 09:29:13,938+02 INFO
[org.ovirt.engine.core.bll.SerialChildCommandsExecutionCallback]
(EE-ManagedThreadFactory-engineScheduled-Thread-84)
[c957e011-37e0-43aa-abe7-9bb633c38c5f] Command 'LiveMigrateDisk' id:
'8174c74c-8ab0-49fa-abfc-44d8b7c691e0' child commands
'[03672b60-443b-47ba-834c-ac306d7129d0,
562522fc-6691-47fe-93bf-ef2c45e85676]' executions were completed, status
'FAILED'

2019-07-18 09:29:15,019+02 ERROR
[org.ovirt.engine.core.bll.storage.lsm.LiveMigrateDiskCommand]
(EE-ManagedThreadFactory-engineScheduled-Thread-1)
[c957e011-37e0-43aa-abe7-9bb633c38c5f] Ending command
'org.ovirt.engine.core.bll.storage.lsm.LiveMigrateDiskCommand' with failure