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

[Digimer]

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.

-- 
Digimer
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