[Pacemaker] Fencing configuration with pcmk_host_map argument

[Thibaut Pouzet]

Le 05/02/2013 16:57, Marek Grac a écrit :
> Hi,
>
> On 02/05/2013 03:24 AM, Andrew Beekhof wrote:
>> I cleared the IPMI configuration and kept only the two WTI fencing
>> Primitives in my configuration to make it as simple as possible :
>>
>> primitive wti_fence01 stonith:fence_wti \
>>          params ipaddr="192.168.0.7" action="reboot" verbose="true"
>> pcmk_host_check="static-list" pcmk_host_list="fence01.domain"
>> pcmk_host_map="fence01.domain:1,5" login_timeout="20" 
>> shell_timeout="20" \
>>          op monitor interval="30s"
>> primitive wti_fence02 stonith:fence_wti \
>>          params ipaddr="192.168.0.7" action="reboot" verbose="true"
>> pcmk_host_check="static-list" pcmk_host_list="fence02.domain"
>> pcmk_host_map="fence02.domain:2,6"
>> It is possible that fence_wti doesn't support multiple port values, or
>> supports them differently.
>> Marek (CC'd) should be able to comment definitively.
>>
> This is right, fence agents (all of them) can be used only with one 
> port value.
>
> m,
>
> _______________________________________________
> Pacemaker mailing list: Pacemaker at oss.clusterlabs.org
> http://oss.clusterlabs.org/mailman/listinfo/pacemaker
>
> Project Home: http://www.clusterlabs.org
> Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
> Bugs: http://bugs.clusterlabs.org
>
Hi Marek, thank you very much for the quick reply.

When I read you (Marek & Andrew), I feel like there is something odd 
here. I have a cluster with two nodes, a redundant ring, two fencing 
methods installed (IPMI, WTI), and each node of this cluster has a dual 
power supply. This configuration should prevent me from a single failure 
anywhere in my system (at least, I hope so).

You are telling me that I cannot use the WTI fence agent to fence one of 
my node because it can only shut one port at a time ?

Maybe I can understant that the fence_agent is only able to shut one 
port at a time. But, what about stonithd's argument "pcmk_host_map" ? I 
thought that it could be the glue I needed here; Let's say I have this : 
pcmk_host_map="fence02.domain:2,6", and this node needs to be fenced. I 
thought that stonithd would do the following (somehow) :

* Shut down (off) port 2 (and make sure the port is actually OFF)
* Shut down (off) port 6 (and make sure the port is actually OFF)
* Power up (on) port 2 (..)
* Power up (on) port 6 (..)

This would be done with four calls to fence_wti. If one "off" action 
fails, stonithd would believe that it could not fence properly the node 
and try another fencing method (i.e. IPMI in my case).

If this is not the purpose of "pcmk_host_map", then I guess I will have 
to rewrite fence_wti to handle my situation properly.

Thibaut.