[ovirt-users] migrate to hosted engine

[Simone Tiraboschi]

On Sun, Mar 12, 2017 at 7:57 AM, Yedidyah Bar David <didi at redhat.com> wrote:

> On Fri, Mar 10, 2017 at 3:43 PM, Devin A. Bougie
> <devin.bougie at cornell.edu> wrote:
> > Hi, All.  We have an ovirt 4.1 cluster setup using multiple paths to a
> single iSCSI LUN for the data storage domain.  I would now like to migrate
> to a hosted engine.
> >
> > I setup the new engine VM, shutdown and backed-up the old VM, and
> restored to the new VM using engine-backup.  After updating DNS to change
> our engine's FQDN to point to the hosted engine, everything seems to work
> properly.  However, when rebooting the entire cluster, the engine VM
> doesn't come up automatically.
>
> I am aware that the above flow is technically possible - nothing stops
> you from doing it - but it's not the standard/supported/expected way
> to deploy a hosted-engine. You must use 'hosted-engine --deploy' for
> that.
> Nice try, though :-) Will be an interesting exercise to try and
> convert this to a fully-functioning hosted-engine, but I'd personally
> not try that on a production system.
>

On the hosted-engine storage domain we have also the lockspace, metadata
and configuration volumes.
They are created at setup time by ovirt-hosted-engine-setup


>
> >
> > Is there anything that now needs to be done to tell the cluster that
> it's now using a hosted engine?
>
> Yes, but it's currently not possible to do this after the fact.
>
> >
> > I started with a  standard engine setup, as I didn't see a way to
> specify multiple paths to a single iSCSI LUN when using "hosted-engine
> --deploy."
>
> I think it's indeed not fully-supported yet [1], but can be done
> manually [2][3].
>
> Simone - are there updates for this? Perhaps we should add this to the
> hosted-engine howto page.
>
> [1] https://bugzilla.redhat.com/show_bug.cgi?id=1193961
> [2] http://lists.ovirt.org/pipermail/users/2015-March/032034.html
> [3] https://bugzilla.redhat.com/show_bug.cgi?id=1193961#c2
>
>
Here we have two distinct things:
- use multiple iSCSI initiators on the host; the best way to achieve this
is configuring an iSCSI bond from the engine once it's running. See
'Configuring iSCSI Multipathing' section on
http://www.ovirt.org/documentation/admin-guide/chap-Storage/
- get multipath connecting to multiple targets on the same SAN: this is
currently not supported by hosted-engine-setup and ovirt-ha-agent


> >
> > Any tips would be greatly appreciated.
> >
> > Many thanks,
> > Devin
> > _______________________________________________
> > Users mailing list
> > Users at ovirt.org
> > http://lists.ovirt.org/mailman/listinfo/users
>
>
>
> --
> Didi
>
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