[ClusterLabs] How to set up fencing/stonith

[Casey & Gina]

> On May 18, 2018, at 1:29 PM, Ken Gaillot <kgaillot at redhat.com> wrote:
>> Perhaps there is a bug in the packaging?
> 
> It sounds like it, or perhaps a portability issue in the agent itself.

There were missing dependencies.  I've resolved that, so now am coming back to trying this...

>>>> pcmk_host_list="<nodeid>" - not sure about this one - I'm
>>>> guessing
>>>> this would actually be the same input as the list I was inputting
>>>> to
>>>> the HOSTLIST parameter with the external/vcenter approach?
>>>> 
>>>> port="<vm_name>" - not sure about this one - with this approach
>>>> would
>>>> I need to issue the above command once for each node in the
>>>> cluster
>>>> with the respective hostnames?
>>> 
>>> The above command presumes one fence device per node. I'm guessing
>>> the
>>> VM names are different from their cluster node names. You could do
>>> the
>>> same thing with a single device using the pcmk_host_map parameter:
>>> 
>>> pcmk_host_map="node1:vm1;node2:vm2;etc."
>> 
>> Ahh, so it's either port= or pcmk_host_map=?  So this should look
>> like pcmk_host_map="d-gp2-dbpg0-1:d-gp2-dbpg0-1;..." in my case?  How
>> then is this different from pcmk_host_list?  Or is pcmk_host_list
>> supposed to be something else entirely than what I've guessed?
>> 
>> My cluster node names and vm names are identical in all cases.
> 
> When the names are the same, pcmk_host_list is sufficient.
> pcmk_host_map is the equivalent for when they're different.

Okay, I see that I can get a list of stonith options with `stonith describe fence_vmware_soap`.  However, this isn't terribly detailed.  Is there a command to get more detailed information, like a man page would?  I did look at `man stonithd` but that doesn't clarify things further either.  I apologize if there's documentation somewhere that I could be reading instead of posting questions here...anyways here are my immediate questions after looking at the above:

1.  I see that it says "action" is required, but is missing in the example `pcs stonith create ...` command.  Is this something variable provided by pacemaker rather than part of the configure command?

2.  How should pcmk_host_list contents be formatted?  A comma-separated list like "hostname1,hostname2,hostname3"?  Based on the example value provided for pcmk_host_map, I guess it may be semicolons instead of commas?  I did find a little more detail in `man stonithd`, but it still doesn't specify how this parameter's value should be formatted.

3.  I see that "port" is required and am still unsure of what this should be set to.  Describe says "Physical plug number on device, UUID or identification of machine".  When you say "the above command presumes one fence device per node", is this a requirement for the fence_vmware_soap device, or is there a different syntax available?  I don't understand the "one device per node" versus "one device for the cluster" concept very well.  Is a single device for the cluster worse idea for some reason?  For a 3-node cluster with one device per node, do I need to create 3 different stonith devices, with port=<hostname> for each different host in the cluster, but all of the nodes in the pcmk_host_list parameter?

Thank you for any insights,
-- 
Casey