First off, a replica 2 gluster volume is not recommended if you want to survive power loss - you need to have a replica 3 gluster volume.

>From engine logs, I see "Could not connect host to Data Center(Storage issue)" but there are no errors in the attached vdsm.log. Can you provide the relevant vdsm log and also the gluster mount logs?

What's the output of "gluster volume heal <volname> info" ?

----- Original Message -----
> From: "Robin Vanderveken" <rvanderveken@dlttechnologies.com>
> To: users@ovirt.org
> Sent: Monday, July 25, 2016 2:01:24 PM
> Subject: [ovirt-users] oVirt 4 master storage down - unable to activate       after power loss
>
> Dear oVirt users
>
> I've been having several problems with my oVirt nodes utilising GlusterFS
> after simulating a power loss.
>
> Our testing setup for oVirt consists of 3 nodes, 2 with GlusterFS storage and
> 1 just for computing. Everything seems to be setup correct and was working
> correctly. Then after simulating a power loss the master storage goes down,
> and therefore the VMs and data center go down as well.
>
> I checked the GlusterFS configuration and it seems to be correct (see
> attachment). I checked the oVirt configuration and it seems to be correct
> (see attachment). I tried putting several Nodes in Maintenace several times,
> even putting in maintenance and reinstalling them. Only when putting the
> nodes in maintenance (and choosing to stop the GlusterFS service) triggers
> Contending on the other Nodes. Only then there is a chance that a Node goes
> from Contending to SPM, which does not always happen. After trying this
> several times I got a main Node to become SPM, but the master storage
> remains down. When I select the master storage, go in the Data center,
> select the data center and click Activate, then both the master storage and
> the data center go in the state Locked for a few seconds and then Inactive
> again.
>
> Then I upgraded to oVirt 4 ( oVirt Engine Version: 4.0.0.6-1.el7.centos) and
> tried everything again, resulting in the same result.
>
> I searched online and found this mailing list which is very similar:
> http://lists.ovirt.org/pipermail/users/2014-August/026905.html .
> Unfortunately the solution was not posted/mailed. I also found this:
> https://www.mail-archive.com/users@ovirt.org/msg08105.html suggesting the
> kernel version is not correct, but I am unsure how to check this.
>
> In the attachment I added relevant logs:
> - GlusterFS service on both main nodes
> - /var/log/vdsm/vdsm.log , /var/log/vdsm/supervdsm.log , /var/log/messages ,
> /var/log/sanlock.log , /var/log/ovirt-engine/engine. log-20160725.gz ,
> /var/log/ovirt-engine/engine.log of the oVirt engine
> as attachments (I clicked on Activate on the data center at 9:45:30 am GMT).
> It can be possible that I need to send different engine logs, please tell me
> if necessary. Any help would be highly appreciated.
>
> Kind regards
> Robin Vanderveken
>
> --
> Robin Vanderveken
> DLT Technologies
> Tel. +352 691 412 922
>
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