[ClusterLabs] DLM, cLVM, GFS2 and OCFS2 managed by systemd instead of crm ?

[Roger Zhou]

Hi Bernd,

Apart from Ken's insights.

I try to put it simple between systemd vs. pacemaker:

pacemaker does manage dependencies among nodes, well, systemd just not.

Cheers,
Roger

On 10/16/19 5:16 AM, Ken Gaillot wrote:
> On Tue, 2019-10-15 at 21:35 +0200, Lentes, Bernd wrote:
>> Hi,
>>
>> i'm a big fan of simple solutions (KISS).
>> Currently i have DLM, cLVM, GFS2 and OCFS2 managed by pacemaker.
>> They all are fundamental prerequisites for my resources (Virtual
>> Domains).
>> To configure them i used clones and groups.
>> Why not having them managed by systemd to make the cluster setup more
>> overseeable ?
>>
>> Is there a strong reason that pacemaker cares about them ?
>>
>> Bernd
> 
> Either approach is reasonable. The advantages of keeping them in
> pacemaker are:
> 
> - Service-aware recurring monitor (if OCF)
> 
> - If one of those components fails, pacemaker will know to try to
> recover everything in the group from that point, and if necessary,
> fence the node and recover the virtual domain elsewhere (if they're in
> systemd, pacemaker will only know that the virtual domain has failed,
> and likely keep trying to restart it fruitlessly)
> 
> - Convenience of things like putting a node in standby mode, and
> checking resource status on all nodes with one command
> 
> If you do move them to systemd, be sure to use the resource-agents-deps
> target to ensure they're started before pacemaker and stopped after
> pacemaker.
>