[ClusterLabs] Pacemaker not always selecting the right stonith device

[Andrei Borzenkov]

On Tue, Jul 19, 2016 at 6:33 PM, Martin Schlegel <martin at nuboreto.org> wrote:
>> > [...]
>> >
>> > primitive p_ston_pg1 stonith:external/ipmi \
>> >  params hostname=pg1 ipaddr=10.148.128.35 userid=root
>> > passwd="/var/vcap/data/packages/pacemaker/ra-tmp/stonith/PG1-ipmipass"
>> > passwd_method=file interface=lan priv=OPERATOR
>> >
>> > primitive p_ston_pg2 stonith:external/ipmi \
>> >  params hostname=pg2 ipaddr=10.148.128.19 userid=root
>> > passwd="/var/vcap/data/packages/pacemaker/ra-tmp/stonith/PG2-ipmipass"
>> > passwd_method=file interface=lan priv=OPERATOR
>> >
>> > primitive p_ston_pg3 stonith:external/ipmi \
>> >  params hostname=pg3 ipaddr=10.148.128.59 userid=root
>> > passwd="/var/vcap/data/packages/pacemaker/ra-tmp/stonith/PG3-ipmipass"
>> > passwd_method=file interface=lan priv=OPERATOR
>> >
>> > location l_pgs_resources { otherstuff p_ston_pg1 p_ston_pg2 p_ston_pg3 }
>> > resource-discovery=exclusive \
>> >  rule #uname eq pg1 \
>> >  rule #uname eq pg2 \
>> >  rule #uname eq pg3
>> >
>> > location l_ston_pg1 p_ston_pg1 -inf: pg1
>> > location l_ston_pg2 p_ston_pg2 -inf: pg2
>> > location l_ston_pg3 p_ston_pg3 -inf: pg3
>>
>> These constraints prevent each device from running on its intended
>> target, but they don't limit which nodes each device can fence. For
>> that, each device needs a pcmk_host_list or pcmk_host_map entry, for
>> example:
>>
>>  primitive p_ston_pg1 ... pcmk_host_map=pg1:pg1.ipmi.example.com
>>
>> Use pcmk_host_list if the fence device needs the node name as known to
>> the cluster, and pcmk_host_map if you need to translate a node name to
>> an address the device understands.
>
>
> We used the parameter "hostname". What does it do if not that ?

hostname is resource parameter. From pacemaker point of view this is
opaque string and only resource agent knows how to interpret it.

See discussion in another part of this thread. Agent is supposed to
return information based on "hostname" parameter but apparently it
does not understand when pacemaker asks it.