[Linux-cluster] question about number of fencing devices needed for a two node cluster

[Digimer]

On 12/06/2010 04:11 PM, Alvaro Jose Fernandez wrote:
> Hi,
>
> I would like to know about wheter it would suffice for a two-node RHCS
> cluster a single power switch (APC 7921) fencing device. The power
> switch has 8 power outlets and I intend to use four of them for each
> node's dual power supplies.
>
> I know it would be desirable to have two devices for a fully redundant
> configuration, but after reading some examples from the docs (they are
> meant for two power switch), I still cannot understand why a single
> power switch connected to both servers and the switch taking power from
> the UPS, would not be a good configuration. There is a single UPS in the
> environment.
>
> ¿any experiences over this issue?
>
> regards,
>
> alvaro

That is sufficient. The only concern is that the PDU doesn't verify node 
death, so success is returned when the power is cut. This requires a 
little extra testing to make sure that your config is accurate. Once 
setup, use 'fence_node <name>' against either node and ensure that they 
really do go down.

-- 
Digimer
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