[ovirt-users] Unable to start VM after upgrade vom 4.1.9 to 4.2.1 - NPE

[Jan Siml]

Hello,

we have upgrade one of our oVirt engines to 4.2.1 (from 4.1.9) and 
afterwards all nodes too. The cluster compatibility level has been set 
to 4.2.

Now we can't start a VM after it has been powered off. The only hint we 
found in engine.log is:

2018-03-07 14:51:52,504+01 INFO 
[org.ovirt.engine.core.vdsbroker.UpdateVmDynamicDataVDSCommand] 
(EE-ManagedThreadFactory-engine-Thread-25) 
[f855b54a-56d9-4708-8a67-5609438ddadb] START, 
UpdateVmDynamicDataVDSCommand( 
UpdateVmDynamicDataVDSCommandParameters:{hostId='null', 
vmId='a7bc4124-06cb-4909-9389-bcf727df1304', 
vmDynamic='org.ovirt.engine.core.common.businessentities.VmDynamic at 491983e9'}), 
log id: 7d49849e
2018-03-07 14:51:52,509+01 INFO 
[org.ovirt.engine.core.vdsbroker.UpdateVmDynamicDataVDSCommand] 
(EE-ManagedThreadFactory-engine-Thread-25) 
[f855b54a-56d9-4708-8a67-5609438ddadb] FINISH, 
UpdateVmDynamicDataVDSCommand, log id: 7d49849e
2018-03-07 14:51:52,531+01 INFO 
[org.ovirt.engine.core.vdsbroker.CreateVDSCommand] 
(EE-ManagedThreadFactory-engine-Thread-25) 
[f855b54a-56d9-4708-8a67-5609438ddadb] START, CreateVDSCommand( 
CreateVDSCommandParameters:{hostId='0add031e-c72f-473f-ab2f-4f7abd1f402b', 
vmId='a7bc4124-06cb-4909-9389-bcf727df1304', vm='VM [prod-hub-201]'}), 
log id: 4af1f227
2018-03-07 14:51:52,533+01 INFO 
[org.ovirt.engine.core.vdsbroker.vdsbroker.CreateBrokerVDSCommand] 
(EE-ManagedThreadFactory-engine-Thread-25) 
[f855b54a-56d9-4708-8a67-5609438ddadb] START, 
CreateBrokerVDSCommand(HostName = prod-node-210, 
CreateVDSCommandParameters:{hostId='0add031e-c72f-473f-ab2f-4f7abd1f402b', 
vmId='a7bc4124-06cb-4909-9389-bcf727df1304', vm='VM [prod-hub-201]'}), 
log id: 71dcc8e7
2018-03-07 14:51:52,545+01 ERROR 
[org.ovirt.engine.core.vdsbroker.vdsbroker.CreateBrokerVDSCommand] 
(EE-ManagedThreadFactory-engine-Thread-25) 
[f855b54a-56d9-4708-8a67-5609438ddadb] Failed in 'CreateBrokerVDS' 
method, for vds: 'prod-node-210'; host: 'prod-node-210': null
2018-03-07 14:51:52,546+01 ERROR 
[org.ovirt.engine.core.vdsbroker.vdsbroker.CreateBrokerVDSCommand] 
(EE-ManagedThreadFactory-engine-Thread-25) 
[f855b54a-56d9-4708-8a67-5609438ddadb] Command 
'CreateBrokerVDSCommand(HostName = prod-node-210, 
CreateVDSCommandParameters:{hostId='0add031e-c72f-473f-ab2f-4f7abd1f402b', 
vmId='a7bc4124-06cb-4909-9389-bcf727df1304', vm='VM
[prod-hub-201]'})' execution failed: null
2018-03-07 14:51:52,546+01 INFO 
[org.ovirt.engine.core.vdsbroker.vdsbroker.CreateBrokerVDSCommand] 
(EE-ManagedThreadFactory-engine-Thread-25) 
[f855b54a-56d9-4708-8a67-5609438ddadb] FINISH, CreateBrokerVDSCommand, 
log id: 71dcc8e7
2018-03-07 14:51:52,546+01 ERROR 
[org.ovirt.engine.core.vdsbroker.CreateVDSCommand] 
(EE-ManagedThreadFactory-engine-Thread-25) [f855b5
4a-56d9-4708-8a67-5609438ddadb] Failed to create VM: 
java.lang.NullPointerException
at 
org.ovirt.engine.core.vdsbroker.builder.vminfo.LibvirtVmXmlBuilder.lambda$writeInterfaces$23(LibvirtVmXmlBuilder.java:1066)
  [vdsbroker.jar:]

[...]

But this doesn't lead us to the root cause. I haven't found any matching 
bug tickets in release notes for upcoming 4.2.1. Can anyone help here?

Kind regards

Jan Siml