[Pacemaker] Fixed! - Re: Problem with dual-PDU fencing node with redundant PSUs

[Digimer]

On 06/28/2013 06:21 AM, Andrew Beekhof wrote:
> 
> On 28/06/2013, at 5:22 PM, Lars Marowsky-Bree <lmb at suse.com> wrote:
> 
>> On 2013-06-27T12:53:01, Digimer <lists at alteeve.ca> wrote:
>>
>>> primitive fence_n01_psu1_off stonith:fence_apc_snmp \
>>>        params ipaddr="an-p01" pcmk_reboot_action="off" port="1"
>>> pcmk_host_list="an-c03n01.alteeve.ca"
>>> primitive fence_n01_psu1_on stonith:fence_apc_snmp \
>>>        params ipaddr="an-p01" pcmk_reboot_action="on" port="1"
>>> pcmk_host_list="an-c03n01.alteeve.ca"
>>
>> So every device twice, including location constraints? I see potential
>> for optimization by improving how the fence code handles this ... That's
>> abhorrently complex. (And I'm not sure the 'action' parameter ought to
>> be overwritten.)
> 
> I'm not crazy about it either because it means the device is tied to a specific command.
> But it seems to be something all the RHCS people try to do...

Maybe something in the rhcs water cooler made us all mad... ;)

>> Glad you got it working, though.
>>
>>> location loc_fence_n01_ipmi fence_n01_ipmi -inf: an-c03n01.alteeve.ca
>> [...]
>>
>> I'm not sure you need any of these location constraints, by the way. Did
>> you test if it works without them?
>>
>>> Again, this is after just one test. I will want to test it several more
>>> times before I consider it reliable. Ideally, I would love to hear
>>> Andrew or others confirm this looks sane/correct.
>>
>> It looks correct, but not quite sane. ;-) That seems not to be
>> something you can address, though. I'm thinking that fencing topology
>> should be smart enough to, if multiple fencing devices are specified, to
>> know how to expand them to "first all off (if off fails anywhere, it's a
>> failure), then all on (if on fails, it is not a failure)". That'd
>> greatly simplify the syntax.
> 
> The RH agents have apparently already been updated to support multiple ports.
> I'm really not keen on having the stonith-ng doing this.

This doesn't help people who have dual power rails/PDUs for power
redundancy. (Unless I am missing something, I'll re-read the
fence_apc_snmp agent man page/metadata to confirm).

-- 
Digimer
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