[Pacemaker] Using "avoids" location constraint

[Lars Marowsky-Bree]

On 2013-07-08T10:13:50, Digimer <lists at alteeve.ca> wrote:

> >While in general I agree, the above failure case is not likely with
> >DRBD.
> >
> It was one example.

Yes, but the use case here happened to be drbd, and thus replicated (not
shared) storage.

> You are right though, the "good" node would disconnect,
> so the result would be a split-brain.

Not necessarily, if an automatic recovery policy is configured.

> Still a poor outcome easily avoided with fencing.

True - but it is also true that there are scenarios where fencing (in
the traditional sense; effectively, the fact that each DRBD copy is
independent does provide some form of IO isolation) isn't an option, and
where possibly rolling back a transaction (worst case for drbd, I'd
wager) is not considered critical.


Regards,
    Lars

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