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Bug 1116055

Summary: Restarting VDSM during Live snapshot will cause ERROR message in engine
Product: [Retired] oVirt Reporter: Raz Tamir <ratamir>
Component: ovirt-engine-coreAssignee: bugs <bugs>
Status: CLOSED WONTFIX QA Contact: Pavel Stehlik <pstehlik>
Severity: low Docs Contact:
Priority: unspecified    
Version: 3.5CC: amureini, gklein, iheim, michal.skrivanek, ratamir, rbalakri, yeylon
Target Milestone: ---   
Target Release: 3.6.0   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: virt
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2015-03-29 09:08:52 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: Virt RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Attachments:
Description Flags
vdsm and engine logs none

Description Raz Tamir 2014-07-03 15:32:21 UTC
Created attachment 914517 [details]
vdsm and engine logs

Description of problem:
An ERROR message appears when restarting vdsm during live snapshot creation.
The snapshot created successfully even though the message:
"Failed to create live snapshot '2' for VM 'vm_0'. VM restart is recommended."
And followed by:
"Failed to complete snapshot '2' creation for VM 'vm_0'."

In engine log a VDSErrorException raised:
2014-07-03 18:26:39,135 ERROR [org.ovirt.engine.core.vdsbroker.vdsbroker.SnapshotVDSCommand] (org.ovirt.thread.pool-6-thread-35) [6b9813f7] Command SnapshotVDSCommand(HostName = aqua-vds4.qa.lab.tlv.redhat.com, HostId = 82893bc5-b294-4b84-a9b9-f044cdb23bda, vmId=e62574cb-5c41-4393-9ec9-a01f718050f6) execution failed. Exception: VDSErrorException: VDSGenericException: VDSErrorException: Failed to SnapshotVDS, error = Snapshot failed, code = 48

Version-Release number of selected component (if applicable):
ovirt-engine-3.5.0-0.0.master.20140605145557.git3ddd2de.el6.noarch

How reproducible:
100%

Steps to Reproduce:
1. start live snapshot
2. restart vdsm 
3.

Actual results:
explained above

Expected results:


Additional info:

Comment 1 Allon Mureinik 2014-07-04 09:04:40 UTC
As far as I can see, the snapshot was created (i.e., createVolume succeeded), but there's no way of knowing if the VM was snapshoted to it or not. Hence, in order to avoid corruption, a restart is recommended.

Raz, a few questions:
1. Can you confirm the above statement?
2. What VDSM did you restart? HSM? SPM?

Comment 2 Raz Tamir 2014-07-08 08:41:24 UTC
Hi Allon,
1. Yes I agree
2. HSM - the vm run on it

Comment 3 Allon Mureinik 2014-07-08 10:20:01 UTC
> 1. Yes I agree
In that case, I'm not sure there's anything better we can do.
In any event, since the createVolume succeeded, it's more of a virt issue than a storage one.

Comment 4 Michal Skrivanek 2014-08-15 13:45:25 UTC
well, it doesn't even sound interesting to solve. Just don't restart the vdsm when it's doing something:)
And when it happens there's no harm really, just the err message and recommendation.

However, Allon, why are we recommending restart of the VM, isn't it enough to just remove the snapshot and say it failed (as a generic recovery when we don't know why or where it failed)

Comment 5 Allon Mureinik 2014-08-17 06:05:42 UTC
(In reply to Michal Skrivanek from comment #4)
> However, Allon, why are we recommending restart of the VM, isn't it enough
> to just remove the snapshot and say it failed (as a generic recovery when we
> don't know why or where it failed)
The point is that you WANTED to snapshot at this time - if the VM is still running, it'll write to the old volumes. If you force the VM to restart, you're forcing it to write to the new volumes. Not perfect, but works.

Comment 6 Michal Skrivanek 2014-08-22 14:26:12 UTC
this bug won't fit into 3.5 release and is being deferred to a later release. If you deeply care about this bug and deserves to be re-evaluated please let me know

Comment 7 Itamar Heim 2015-03-29 09:08:52 UTC
Closing old bugs. If this issue is still relevant/important in current version, please re-open the bug.