[ovirt-users] Fake power management?

Barak Azulay bazulay at redhat.com
Mon Nov 17 22:32:06 UTC 2014


Well you can hack the solution in the form of replacing the fencing master script to always return success (Eli can help you with that),
and define an imaginary fencing device on each host ... meaning that the fencing command will always succeeds.

But this may be risky ... as you might end up with the same VM running on 2 hosts.

And one last note ... when you disconnect one of the hosts in the demo you mentioned, I think you'll be better to disconnect the host that does not run the engine ...

Barak 

----- Original Message -----
> From: "mots" <mots at nepu.moe>
> To: "Barak Azulay" <bazulay at redhat.com>
> Cc: users at ovirt.org
> Sent: Monday, November 17, 2014 12:58:20 PM
> Subject: AW: [ovirt-users] Fake power management?
> 
> Yes, pacemaker manages the engine. That part is working fine, the engine
> restarts on the remaining node without problems.
> It's just that the guests don't come back up until the powered down node has
> been fenced manually.
> 
> -----Ursprüngliche Nachricht-----
> > Von:Barak Azulay <bazulay at redhat.com <mailto:bazulay at redhat.com> >
> > Gesendet: Mon 17 November 2014 11:35
> > An: Patrick Lottenbach <pl at a-bot.ch <mailto:pl at a-bot.ch> >
> > CC: users at ovirt.org <mailto:users at ovirt.org>
> > Betreff: Re: [ovirt-users] Fake power management?
> > 
> > 
> > 
> > ----- Original Message -----
> > > From: "mots" <mots at nepu.moe <mailto:mots at nepu.moe> >
> > > To: users at ovirt.org <mailto:users at ovirt.org>
> > > Sent: Friday, November 14, 2014 4:54:08 PM
> > > Subject: [ovirt-users] Fake power management?
> > > 
> > > Fake power management? Hello,
> > > 
> > > I'm building a small demonstration system for our sales team to take to a
> > > customer so that they can show them our solutions.
> > > Hardware: Two Intel NUC's, a 4 port switch and a laptop.
> > > Engine: Runs as a VM on one of the NUCs, which one it runs on is
> > > determined
> > > by pacemaker.
> > > Storage: Also managed by pacemaker, it's drbd backed and accessed with
> > > iscsi.
> > > oVirt version: 3.5
> > > OS: CentOS 6.6
> > > 
> > > The idea is to have our sales representative (or the potential customer
> > > himself) randomly pull the plug on one of the NUCs to show that the
> > > system
> > > stays operational when part of the hardware fails.
> > 
> > I assume you are aware that the engine might fence the node it is running
> > on ...
> > Or do you use pacemaker to run the engine as well ?
> > 
> > > My problem is that I don't have any way to implement power management, so
> > > the
> > > Engine can't fence nodes and won't restart guests that were running on
> > > the
> > > node which lost power. In pacemaker I can just configure fencing over SSH
> > > or
> > > even disable the requirement to do so completely. Is there something
> > > similar
> > > for oVirt, so that the Engine will consider a node which it can't connect
> > > to
> > > to be powered down?
> > > 
> > > Regards,
> > > 
> > > mots
> > > 
> > > _______________________________________________
> > > Users mailing list
> > > Users at ovirt.org <mailto:Users at ovirt.org>
> > > http://lists.ovirt.org/mailman/listinfo/users
> > > <http://lists.ovirt.org/mailman/listinfo/users>
> > > 
> > 
> 
>



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