[ovirt-devel] hosted-engine setup/migration features for 3.6

[Yedidyah Bar David]

----- Original Message -----
> From: "Yedidyah Bar David" <didi at redhat.com>
> To: "Bob Doolittle" <bob at doolittle.us.com>
> Cc: "users" <users at ovirt.org>, "devel" <devel at ovirt.org>
> Sent: Wednesday, December 3, 2014 3:04:17 PM
> Subject: Re: [ovirt-devel] hosted-engine setup/migration features for 3.6
> 
> ----- Original Message -----
> > From: "Bob Doolittle" <bob at doolittle.us.com>
> > To: "Yedidyah Bar David" <didi at redhat.com>
> > Sent: Wednesday, December 3, 2014 2:50:12 PM
> > Subject: Re: [ovirt-devel] hosted-engine setup/migration features for 3.6
> > 
> > Another issue with that page is that it assumes a remote database. I am not
> > sure what percentage of cases have remote databases but clearly many
> > (most?) do not, since that's not default behavior.
> 
> I agree.
> 
> > So that page definitely
> > needs attention. See:
> > https://bugzilla.redhat.com/show_bug.cgi?id=1099995
> 
> Indeed. Note that this isn't specific to hosted-engine, it's the same for
> any migration using engine-backup to backup/restore, therefore there is
> a link to its page in the top, where this is more detailed.

I now added another note next to the restore text.

> We also have
> a bug [3] to automate this.
> 
> [3] https://bugzilla.redhat.com/show_bug.cgi?id=1064503
> 
> > https://bugzilla.redhat.com/show_bug.cgi?id=1099998
> > 
> > Some of us have wanted to disable global maintenance upon bootup by adding
> > a systemd service on Fedora 20 (since you must enable global maintenance to
> > shut it down cleanly), and have found it impossible to create the necessary
> > systemd dependencies. It seems that (at least with 3.4) hosted-engine
> > --set-maintenance --mode=none will return an error for several seconds
> > after all other services have started and it's not clear what can be waited
> > upon in order to issue the command with assurance it will complete
> > successfully. This isn't strictly a setup/migration issue but it is an
> > issue with setting up a desired configuration with hosted-engine. The way
> > to reproduce this is simply to wait until gdm-greeter displays the login
> > prompt, ssh into the system and execute hosted-engine --set-maintenance
> > --mode=none and observe the error. Or create a systemd service that depends
> > upon (waits for) the latest-possible service, try executing the command
> > there, and observe the error. Ideally there would be some external
> > observable event which a systemd service could depend upon, when
> > hosted-engine is ready to do its thing.
> 
> Adding Jiri for that. Do you have an open bug?
> 
> Thanks,
> 
> > 
> > Regards,
> >     Bob
> > 
> > 
> > On Wed, Dec 3, 2014 at 2:59 AM, Yedidyah Bar David <didi at redhat.com> wrote:
> > 
> > > Hi all,
> > >
> > > We already have quite a lot of open ovirt-hosted-engine-setup bugs for
> > > 3.6
> > > [1].
> > >
> > > Yesterday I tried helping someone on irc who planned to migrate to
> > > hosted-engine
> > > manually, and without knowing (so it seems) that such a feature exists.
> > > He
> > > had
> > > an engine set up on a physical host, prepared a VM for it, and asked
> > > about
> > > migrating
> > > the engine to the VM. In principle this works, but the final result will
> > > be a
> > > hosted-engine, where the engine manages a VM the runs itself, without
> > > knowing it,
> > > and without HA.
> > >
> > > The current recommended migration flow is described in [2]. This page is
> > > perhaps
> > > a bit outdated, perhaps missing some details etc., but principally works.
> > > The main
> > > issue with it, AFAICT after discussing this a bit with few people, is
> > > that
> > > it
> > > requires a new clean host.
> > >
> > > I'd like to hear what people here think about such and similar flows.
> > >
> > > If you already had an engine and migrated to hosted-engine, what was
> > > good,
> > > what
> > > was bad, what would you like to change?
> > >
> > > If you plan such a migration, what do you find missing currently?
> > >
> > > [1] http://red.ht/1vle8Vv
> > > [2] http://www.ovirt.org/Migrate_to_Hosted_Engine
> > >
> > > Best,
> > > --
> > > Didi
> > > _______________________________________________
> > > Devel mailing list
> > > Devel at ovirt.org
> > > http://lists.ovirt.org/mailman/listinfo/devel
> > >
> > 
> 
> --
> Didi
> 
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> 

Best,
-- 
Didi