On Thu, Oct 30, 2008 at 02:01, Andreas Mock <[EMAIL PROTECTED]> wrote:
> Andrew Beekhof schrieb:
>>
>> Not if the power loss includes power loss to the stonith device (which
>> as you said, is what happens in your case).
>> The only real solution is to add a stonith mechanism that doesn't have
>> this design problem (possibly in addition to the existing one).
>>
>> Unfortunately, anything else leaves you as vulnerable as if stonith
>> wasn't enabled in the first place.
>>
>
> Hi Andrew,
>
> you must be more precise: "...as vulnerable to a total power failure of a
> node as if stonith wasn't enabled in the first place."
> You get a reward of enabling this stonith device compared to have no stonith
> at all, don't you? :-)
> (e.g. software bugs,

yes

> ressource overload,

yes

> network failures of heartbeat-link)

of just the heartbeat link yes...

but a general network failure looks the same as a power outage.
in both cases the other side (including the stonith device) are unresponsive.

> This special scenario of power outage of one node is IMHO not very likely in
> a productive HA environment.
> Why? Every node has two power supplies. Every power supply is connected to
> an extra APS which is
> connected to an extra power line. Every power supply is monitored for
> failure to be replaced in time.
> If you can't or don't want to afford this kind of redundancy you have to
> live with a service outage in that
> special scenario.

agreed
mostly i was cautioning against doing something to force the cluster to continue

because doing that compromises the clusters behavior in other scenarios too

> But to nail it down: Everything is better than mounting a regular filesystem
> from more than one node!! :-)

well yeah ;-)
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