[Pacemaker] double stonith device

[Christian Zoffoli]

Il 05/04/2011 01:21, Lars Marowsky-Bree ha scritto:
> On 2011-04-04T15:34:16, Christian Zoffoli <czoffoli at xmerlin.org> wrote:
> 
>> I cannot connect both PSUs to a single PDU without loosing power source
>> reduncancy (I have dual UPS, dual power lines and so on).
> 
> Yes. Because the alternative is to lose the ability to fence the node if
> you lose one of the fencing devices. (I assume you'd be unable to
> confirm the fence if one of them was without power?)

if the APC fence device is not available I can check the status using
IPMI ...but considering only the APC switched PDU ...you are absolutely
right

> You need to look at the larger picture: even though each node is only
> on one power supply, the whole cluster is on two.

...there is a side effect ...sometimes we need to bring down 1 power
circuit ...for maintenance or whatever ...so we need two separate power
circuit to not impact on availability

> Alternatively, use a mechanism like SBD which doesn't fence via the
> power device, but uses the shared storage.

...interesting ...I'll have a look also to SBD

Thank you

Christian