[Linux-HA] Re: [Pacemaker] Ordered attribute of clone resources

[Lars Marowsky-Bree]

On 2008-01-26T22:32:21, Andreas Mock <Andreas.Mock at web.de> wrote:

> this can have an impact on monitoring stonith resource agents if you
> want to use clones. There are many stonith devices which do allow only
> extactly one connection at a time. The monitor action is often implemented
> to connect to the stonith device to see if it's alive.
> Now if you use clones, and the stonith RA is run on more then one node
> it could happen that the monitor action is triggered at the same time
> resulting in one monitor action to fail because two instances try to connect
> to the same stonith device.
> 
> Am I wrong with that conclusion?

No, you are not.

Such a device should either not be handled by a clone.

Or instead by an m/s resource - where only the master performs the
monitor; but this gives you maximum complexity while not providing any
benefit over handling it as a primitive resource - fancy, though ;-) 


Regards,
    Lars

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Teamlead Kernel, SuSE Labs, Research and Development
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