[Pacemaker] Fencing: Where?

[David Vossel]

----- Original Message -----
> From: "Michael Schwartzkopff" <ms at sys4.de>
> To: "The Pacemaker cluster resource manager" <pacemaker at oss.clusterlabs.org>
> Sent: Monday, December 2, 2013 4:38:12 AM
> Subject: Re: [Pacemaker] Fencing: Where?
> 
> Am Montag, 2. Dezember 2013, 13:15:23 schrieb Nikita Staroverov:
> > > Hi,
> > > 
> > > as far as I unterstood RH is going to do all infrastructure in the cman
> > > layer and user pacemaker only for resource management. Whith this setup
> > > fencing also will be a job of the fenced of the cman package.
> > > 
> > > This design has its advantages: If descisions are taked on a low level,
> > > all
> > > parts of the cluster have the chance to know about theses descisions.
> > > 
> > > BUT: If pacemaker needs to fence a node, it has no possibility to so so
> > > any
> > > more. Imagine a resource will not stop and pacemaker would like to fence
> > > that node to go on. How would that situation be handled with fencing in
> > > cman?
> > > 
> > > Is there any way pacemaker can tell cman about it's wish to fence an
> > > other
> > > nore?
> > > 
> > > The only solution I can think of is to delegate the fencing in cman to
> > > pacemaker. So both layers are able to fence. But this cannot be a good
> > > solution, since we have to setup fencing on two places.
> > > 
> > > Thanks for fruitful discussion.
> > > 
> > > 
> > > Mit freundlichen Grüßen,
> > > 
> > > Michael Schwartzkopff
> > 
> > fence_pcmk does the job. Have you got any troubles with it?
> 
> No. I use it now. But setting up fencing in two places
> - cman -> links to pacemaker
> - pamcemaker
> 
> it not very nice to configure fencing in two places.

You aren't really configuring fencing devices in two places.  The fence_pcmk device in cluster.conf is just telling 'fenced' to forward all its fencing requests to stonith-ng.  This allows us to configure all the real fencing devices in one place now using pacemaker.

-- Vossel

> 
> Is there any way that pacemaker can tell cman about it's fencing descisions
>
> 
> 
> --
> Mit freundlichen Grüßen,
> 
> Michael Schwartzkopff
> 
> --
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