[ClusterLabs] set node in maintenance - stop corosync - node is fenced - is that correct ?

[Lentes, Bernd]

----- On Oct 16, 2017, at 10:57 PM, kgaillot kgaillot at redhat.com wrote:


>> from the Changelog:
>> 
>> Changes since Pacemaker-1.1.15
>>   ...
>>   + pengine: do not fence a node in maintenance mode if it shuts down
>> cleanly
>>   ...
>> 
>> just saying ... may or may not be what you are seeing.
>> 
>> Short term "workaround" may be to do things differently.
>> Maybe just set the cluster wide maintenance mode, not per node?
> 
> Sounds right.
> 
> Another thing to keep in mind is that even if pacemaker doesn't fence
> the node, if you use DLM, DLM might fence the node (it doesn't know
> about or respect any pacemaker maintenance/unmanaged settings).
> 
> I'd stop pacemaker before stopping corosync, in any case. In
> maintenance mode, that should be fine. I don't think a running
> pacemaker would be able to reconnect to corosync after corosync comes
> back.
> 

As Ulrich already mentioned the suse openais init script is responsible for both, pacemaker and corosync.

I have DLM in combination with cLVM, maybe that's the culprit. I will test to stop the DLM and cLVM resource before doing maintenance and stop corosync, maybe then it's not fenced.
I'm thinking of stopping using DLM in conjunction with cLVM and a SAN. I read an article (http://www.admin-magazine.com/Articles/Live-Migration , see chapter "The Weakest Link")
saying that DLM is tricky and not completely stable. It mentioned that Bastian Blank, who seems to be a maintainer of the Debian team, deactivated cLVM in the debian kernel. But the article is from 2013, so i'm not pretty sure.
Maybe DRBD and no SAN, so no DLM would be the better solution.


Bernd
 

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