On 8/2/07, Klemens Kittan <[EMAIL PROTECTED]> wrote:
> Hello list,
>
> I've got a problem with the following part of the DRBD Howto at
> http://www.linux-ha.org/DRBD/HowTov2
>
> -----------------
> Specifying the nodes where drbd can be run
>
> If you only have a two node cluster, you could skip this step, because
> obviously, it can only run on those two. If you want to run drbd0 on two out
> of more nodes only, you will have to tell the cluster about this constraint:
>
> <rsc_location id="drbd0-placement-1" rsc="ms-drbd0">
>  <rule id="drbd0-rule-1" score="-INFINITY">
>   <expression id="exp-01" value="xen-1" attribute="#uname" operation="eq"/>
>   <expression id="exp-02" value="xen-2" attribute="#uname" operation="eq"/>
>  </rule>
> </rsc_location>
>
> These two constraints tell the Policy Engine that, first, drbd0 can not run
> anywhere else except on xen-1 or xen-2. Second, they tell the PE that yes, it
> can run on those two.
> ------------------
>
> If I understand the logic of the rules correctly, the expressions will be
> concatenated by 'and' (the default), and the first expression being true
> if and only if evaluated on (or for ?) node xen-1, the second on xen-2,
> both can never be true, so the rule will never apply.
>
> In my opinion it would make much more sense if the operation attributes of the
> expressions where 'ne' instead of 'eq'?

yep,  would you mind updating that page for us?

>
> Furthermore I think that the last two sentences of the excerpt above are
> somewhat misleading. How can one rule tell two different things ...?

only the first part is true.
the second part is implied by setting symmetric-cluster=true
_______________________________________________
Linux-HA mailing list
[email protected]
http://lists.linux-ha.org/mailman/listinfo/linux-ha
See also: http://linux-ha.org/ReportingProblems

Reply via email to