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

[Lars Marowsky-Bree]

On 2013-06-29T09:22:20, Andrew Beekhof <andrew at beekhof.net> wrote:

> > This doesn't help people who have dual power rails/PDUs for power
> > redundancy.
> I'm yet to be convinced that having two PDUs is helping those people in the first place.
> If it were actually useful, I suspect more than two/three people would have asked for it in the last decade.

I admit that after thinking about it some more, I do see the appeal for
certain configurations.

Like Digimer wrote, you do need a double failure for this two-layer
fencing mechanism to fail (node burned + one grid down).

While I personally prefer the self-fence mechanisms, I think this does
make sense for other environments where multiple redundant power
supplies are desired.

And apparently, this is one of the scenarios for which fence topology
was created and supports multiple devices per level. I'd venture the
opinion that the current implementation of "multiple devices per level"
is broken (since it requires work-arounds like digimer posted).

I don't have a very strong opinion, but if this is something RHEL
customers had before, I'd suggest you don't want to force that complex
configuration on them. And on you to support. ;-)


Regards,
    Lars

-- 
Architect Storage/HA
SUSE LINUX Products GmbH, GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer, HRB 21284 (AG Nürnberg)
"Experience is the name everyone gives to their mistakes." -- Oscar Wilde