[ovirt-users] restore of backup fail when Migrating to ovirt-engine 4.0

[Yedidyah Bar David]

On Tue, Jun 28, 2016 at 10:53 AM, Ricky Schneberger
<ricky at schneberger.se> wrote:
> On 2016-06-27 19:15, Fernando Fuentes wrote:
>
> Ricky,
>
> I am under the impression that the DB migration was implemented in
> release 3.6.6.
>
> I might be wrong.
>
> https://www.ovirt.org/release/3.6.6/
>
> What's New in 3.6.6?
> Enhancement
> oVirt Engine
>
> BZ 1241149 [RFE] Provide way to preform in-cluster upgrade of hosts from
> el6->el7.
> BZ 1332463 [RFE] restore: ensure that 3.6 on el6 backup can be restored
> on 3.6 on el7
> Feature:
>
> Allow engine-backup on el7 to restore backups taken on el6.
>
> Reason:
>
> engine 4.0 does not support el6. Users that want to upgrade from 3.6 on
> el6 to 4.0 on el7 have to do this by backing up the engine on 3.6/el6
> and restore on 4.0/el7.
>
> This feature, backported from 4.0, allows to do such a migration also in
> 3.6.
>
> Result:
>
> Using this flow, it's possible to migrate a el6 setup to el7:
>
> On the existing engine machine run:
> 1. engine-backup --mode=backup --file=engine-3.6.bck --log=backup.log
>
> On a new el7 machine:
> 2. Install engine, including dwh if it was set up on el6.
> 3. Copy engine-3.6.bck to the el7 machine
> 4. engine-backup --mode=restore --file=engine-3.6.bck --log=restore.log
> --provision-db --no-restore-permissions
> 5. engine-setup
>
> Check engine-backup documentation for other options, including using
> remote databases, extra grants/permissions, etc.
>
>
> One step forward, two backward....
>
> - upgrade the old EL6 to ovirt 3.6.6
> - engine-backup --mode=backup --file=engine-backup.tar.gz --log=backup.log
> - install http://resources.ovirt.org/pub/yum-repo/ovirt-release40.rpm, to
> have ovirt-engine 4.0.0.6.
> - yum install ovirt-engine
> - engine-backup --mode=restore --no-restore-permissions --provision-db
> --file=engine-backup.tar.gz --log=engine-backup-restore.log
>
> Then I got this error...
>
> "Preparing to restore:
> - Unpacking file 'engine-backup.tar.gz'
> Restoring:
> - Files
> ------------------------------------------------------------------------------
> Please note:
>
> Operating system is different from the one used during backup.
> Current operating system: centos7
> Operating system at backup: centos6
>
> Apache httpd configuration will not be restored.
> You will be asked about it on the next engine-setup run.
> ------------------------------------------------------------------------------
> Provisioning PostgreSQL users/databases:
> - user 'engine', database 'engine'
> Restoring:
> FATAL: Can't connect to database 'ovirt_engine_history'. Please see
> '/usr/bin/engine-backup --help'."
>

The backup/restore here is just like normal ones, so for details you can read
the output of 'engine-backup --help' or [1].

In your specific case, you seem to have dwh in your backup.

To restore it, you have to either prepare a database with the same credentials
as the one used in the old machine, or, if it was automatically-provisioned by
engine-setup, you can pass the option '--provision-dwh-db' to make engine-backup
create it for you.

I think I should add an option '--provision-all-databases' or something like
that. Didn't feel very good about it so never done, and no-one asked for it...

Best regards,

[1] http://www.ovirt.org/develop/release-management/features/engine/engine-backup/

> I have attached the engine-backup-restore.log.
>
> //Ricky
>
>
>
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>



-- 
Didi