[Pacemaker] Fixed! - Re: Problem with dual-PDU fencing node with redundant PSUs

[Dejan Muhamedagic]

On Mon, Jul 01, 2013 at 11:53:29AM -0400, Digimer wrote:
> On 07/01/2013 04:52 AM, Dejan Muhamedagic wrote:
> > Right. It is often missed that actually more than one failure is
> > required for that setup to fail. In case of dual PDU/PSU/UPS an
> > IPMI based fencing is sufficient.
> 
> You are right, of course. Imagine though that the IPMI BMC's network
> port or cable could have silently failed some time before the node
> failed. Yes, this is two simultaneous failues so not an overall SPoF,
> but likely enough that it should be addressed.
> 
> If you've already setup redundant power, then it strikes me as fairly
> easy to use your PDUs as a backup fence method.
> 
> Now all this said, you'll note in the mailing lists and IRC that I don't
> tell people they should have two methods. If people setup just IPMI
> fencing, I am happy. It's a question of how careful do you want/need to
> be, after that. For me, one fence method is not enough.

I suppose that you're supporting a few clusters. How often does
it happen that nodes get fenced? And why? And did you in those
cases needed to use the backup fence device?

Thanks,

Dejan

> -- 
> Digimer
> Papers and Projects: https://alteeve.ca/w/
> What if the cure for cancer is trapped in the mind of a person without
> access to education?
> 
> _______________________________________________
> Pacemaker mailing list: Pacemaker at oss.clusterlabs.org
> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
> 
> Project Home: http://www.clusterlabs.org
> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
> Bugs: http://bugs.clusterlabs.org