-----Ursprüngliche Nachricht-----
Von: Yedidyah Bar David [mailto:didi@redhat.com]
Gesendet: Mittwoch, 28. März 2018 10:06
An: Sven Achtelik
Cc: users(a)ovirt.org
Betreff: Re: [ovirt-users] Recovering oVirt-Engine with a backup before
upgrading to 4.2
On Tue, Mar 27, 2018 at 9:14 PM, Sven Achtelik <Sven.Achtelik(a)eps.aero>
wrote:
> Hi All,
>
>
>
> I’m still facing issues with my HE engine. Here are the steps that I
> took to end up in this situation:
>
>
>
> - Update Engine from 4.1.7 to 4.1.9
>
> o That worked as expected
>
> - Automatic Backup of Engine DB in the night
>
> - Upgraded Engine from 4.1.9 to 4.2.1
>
> o That worked fine
>
> - Noticed Issues with the HA support for HE
>
> o Cause was not having the latest ovirt-ha agent/broker version on hosts
>
> - After updating the first host with the latest packages for the
> Agent/Broker engine was started twice
>
> o As a result the Engine VM Disk was corrupted and there is no Backup of
> the Disk
>
> o There is also no Backup of the Engine DB with version 4.2
>
> - VM disk was repaired with fsck.ext4, but DB is corrupt
>
> o Can’t restore the Engine DB because the Backup DB from Engine V 4.1
>
> - Rolled back all changes on Engine VM to 4.1.9 and imported Backup
>
> o Checked for HA VMs to set as disabled and started the Engine
>
> - Login is fine but the Engine is having trouble picking up and
> information from the Hosts
>
> o No information on running VMs or hosts status
>
> - Final Situation
>
> o 2 Hosts have VMs still running and I can’t stop those
>
> o I still have the image of my corrupted Engine VM (v4.2)
>
>
>
> Since there were no major changes after upgrading from 4.1 to 4.2,
> would it be possible to manually restore the 4.1 DB to the 4.2 Engine
> VM to this up and running again or are there modifications made to the
> DB on upgrading that are relevant for this ?
engine-backup requires restoring to the same version used to take the backup,
with a single exception - on 4.0, it can restore 3.6.
It's very easy to patch it to allow also 4.1->4.2, search inside it for
"VALID_BACKUP_RESTORE_PAIRS". However, I do not think anyone ever
tested this, so no idea might break. In 3.6->4.0 days, we did have to fix a few
other things, notably apache httpd and iptables->firewalld:
https://bugzilla.redhat.com/show_bug.cgi?id=1318580
> All my work on rolling back to 4.1.9 with the DB restore failed as the
> Engine is not capable of picking up information from the hosts.
No idea why, but not sure it's related to your restore flow.
> Lessons learned is to always make a copy/snapshot of the engine VM
> disk before upgrading anything.
If it's a hosted-engine, this isn't supported - see my reply on the list ~ 1
hour
ago...
> What are my options on getting
> back to a working environment ? Any help or hint is greatly appreciated.
Restore again with either methods - what you tried, or patching engine-
backup and restore directly into 4.2 - and if the engine fails to talk to the hosts,
try to debug/fix this.
If you suspect corruption more severe that just the db, you can install a fresh
engine machine from scratch and restore to it. If it's a hosted-engine, you'll
need to deploy hosted-engine from scratch, check docs about hosted-engine
backup/restore.
I read through those documents and it seems that I would need an extra Host/Hardware which
I don't have.
So how would I be able to get a new setup working when I would like to use the
Engine-VM-Image ? At this point it sounds like I would have to manually reinstall the
machine that is left over and running. I'm lost at this point.