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<div>Hi Didi,</div>
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<div>my backups where taken with the end. Backup utility. I have 3 Data centers, two of them with just one host and the third one with 3 hosts running the engine. The backup three days old, was taken on engine version 4.1 (4.1.7) and the restored engine is
running on 4.1.9. I have three HA VMs that would be affected. All others are just normal vms. Sounds like it would be the safest to shut down the HA vm S to make sure that nothing happens ? Or can I disable the HA action in the DB for now ?</div>
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<div>Thank you,</div>
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<div>Sven</div>
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<div dir="auto" style="font-size:85%; color:#575757">Von meinem Samsung Galaxy Smartphone gesendet.</div>
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<div>-------- Ursprüngliche Nachricht --------</div>
<div>Von: Yedidyah Bar David <didi@redhat.com> </div>
<div>Datum: 19.03.18 07:33 (GMT+01:00) </div>
<div>An: Sven Achtelik <Sven.Achtelik@eps.aero> </div>
<div>Cc: users@ovirt.org </div>
<div>Betreff: Re: [ovirt-users] Workflow after restoring engine from backup </div>
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<div class="PlainText">On Sun, Mar 18, 2018 at 11:45 PM, Sven Achtelik <Sven.Achtelik@eps.aero> wrote:<br>
> Hi All,<br>
><br>
><br>
><br>
> I had issue with the storage that hosted my engine vm. The disk got<br>
> corrupted and I needed to restore the engine from a backup.<br>
<br>
How did you backup, and how did you restore?<br>
<br>
Which version was used for each?<br>
<br>
> That worked as<br>
> expected, I just didn’t start the engine yet.<br>
<br>
OK.<br>
<br>
> I know that after the backup<br>
> was taken some machines where migrated around before the engine disks<br>
> failed.<br>
<br>
Are these machines HA?<br>
<br>
> My question is what will happen once I start the engine service<br>
> which has the restored backup on it ? Will it query the hosts for the<br>
> running VMs<br>
<br>
It will, but HA machines are handled differently.<br>
<br>
See also:<br>
<br>
<a href="https://bugzilla.redhat.com/show_bug.cgi?id=1441322">https://bugzilla.redhat.com/show_bug.cgi?id=1441322</a><br>
<a href="https://bugzilla.redhat.com/show_bug.cgi?id=1446055">https://bugzilla.redhat.com/show_bug.cgi?id=1446055</a><br>
<br>
> or will it assume that the VMs are still on the hosts as they<br>
> resided at the point of backup ?<br>
<br>
It does, initially, but then updates status according to what it<br>
gets from hosts.<br>
<br>
But polling the hosts takes time, especially if you have many, and<br>
HA policy might require faster handling. So if it polls first a<br>
host that had a machine on it during backup, and sees that it's<br>
gone, and didn't yet poll the new host, HA handling starts immediately,<br>
which eventually might lead to starting the VM on another host.<br>
<br>
To prevent that, the fixes to above bugs make the restore process<br>
mark HA VMs that do not have leases on the storage as "dead".<br>
<br>
> Would I need to change the DB manual to let<br>
> the engine know where VMs are up at this point ?<br>
<br>
You might need to, if you have HA VMs and a too-old version of restore.<br>
<br>
> What will happen to HA VMs<br>
> ? I feel that it might try to start them a second time. My biggest issue is<br>
> that I can’t get a service Windows to shutdown all VMs and then lat them<br>
> restart by the engine.<br>
><br>
><br>
><br>
> Is there a known workflow for that ?<br>
<br>
I am not aware of a tested procedure for handling above if you have<br>
a too-old version, but you can check the patches linked from above bugs<br>
and manually run the SQL command(s) they include. They are essentially<br>
comment 4 of the first bug.<br>
<br>
Good luck and best regards,<br>
-- <br>
Didi<br>
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