[ovirt-users] How to manually restore ovirt-engine from sql dump file?

[Yedidyah Bar David]

On Wed, Dec 30, 2015 at 9:23 PM, Arman Khalatyan <arm2arm at gmail.com> wrote:
> Hello,
> Due to the HW error we lost ovirt-engine db.

Only db? Rest of machine is ok? You also want stuff
in /etc (and /var, somewhat less important).

> We have only recent dump files from
> /var/lib/ovirt-engine/backups/

These are saved during engine-setup, and are backups made
with the version you had _before_ starting the upgrade.

They are meant only for restoration during rollback,
by engine-setup itself, in case it has a problem and tries
to rollback.

> Is it possible to restore database using dump files?

In principle yes, but unless you have a backup of /etc
taken _before_ the last upgrade, you'll have an older
dump with a newer /etc, which might lead to conflicts.

You can try something like that. First on a test system
of course:
1. yum remove ovirt-engine\*
2. yum install ovirt-engine with the exact version you had
before last upgrade. You can check logs in
/var/log/ovirt-engine/setup and/or /var/log/yum.log.
3. Keep (or copy/restore) /etc/ovirt-engine and
/etc/pki/ovirt-engine. If you had dwh/reports you'll need
more files. Also better check the list of backed up files
in the start of the engine-backup script to see what else
it backs up.
4. Restore the db using psql (if <= 3.5) or pg_restore
(if >=3.6). If needed first create one.
5. run engine-setup --offline and see that all seems ok.
6. Then upgrade to latest by running engine-setup without
--offline.

> BTW the VMs are still running without ovirt-engine.

Indeed, but are not managed. Meaning, no ha/scheduling/etc.

Note that if you do try that on a test system, it will immediately
try to manage your hosts. Better prevent that (firewall or
whatever) before you are ready to do that on your live system.

Good luck,
-- 
Didi