[Pacemaker] cman + corosync + pacemaker + fence_scsi

[Andrew Beekhof]

On 24/04/2013, at 11:44 PM, Andreas Mock <Andreas.Mock at web.de> wrote:

> Hi Angel,
> 
> two hints from my side. As you're working with ubuntu
> ask in this list which setup is or will be the best
> concerning corosync + pacemaker. I'm pretty sure
> (but I really don't know) that you'll get the advice
> to drop cman.

Not really, until distros start shipping corosync 2.x it's probably the best option.
If I had my time over again, I would not have written the pacemaker plugin.

> 
> When you use cman + pacemaker than stonithing works
> as following. Use the pcmk-redirect in cman which
> causes that cman delegates stonith commands to
> pacemaker. In pacemaker you have to add the
> stonith agents which use your hardware. You
> have to enable stonithing in pacemaker with
> stonith-enabled="true".
> 
> Another issue with stonithing. In a two node cluster
> you have to configure the stonith agents in a
> way that the remaining part (which ever it is,
> mostly the faster one) is able to shoot the other
> node even when cluster communication is lost.
> When the stonith action is done over the same
> wire as your cluster communication than stonithing
> is meaningless.

Very true

> 
> Best regards
> Andreas Mock
> 
> 
> -----Ursprüngliche Nachricht-----
> Von: Angel L. Mateo [mailto:amateo at um.es] 
> Gesendet: Mittwoch, 24. April 2013 14:49
> An: The Pacemaker cluster resource manager
> Betreff: [Pacemaker] cman + corosync + pacemaker + fence_scsi
> 
> Hello,
> 
> 	I'm trying to configure a 2 node cluster in ubuntu with cman +
> corosync 
> + pacemaker (the use of cman is because it is recommended at pacemaker 
> quickstart). In order to solve the split brain in the 2 node cluster I'm 
> using qdisk. For fencing, I'm trying to use fence_scsi and in this point 
> I'm having the problem. I have attached my cluster.conf.
> 
> xml <node id="/dev/block/8:33" type="normal" uname="/dev/block/8:33"/>
> node myotis51
> node myotis52
> primitive cluster_ip ocf:heartbeat:IPaddr2 \
> 	params ip="155.54.211.167" \
> 	op monitor interval="30s"
> property $id="cib-bootstrap-options" \
> 	dc-version="1.1.6-9971ebba4494012a93c03b40a2c58ec0eb60f50c" \
> 	cluster-infrastructure="cman" \
> 	stonith-enabled="false" \
> 	last-lrm-refresh="1366803979"
> 
> 	At this moment I'm trying just with an IP resource, but at the end
> I'll 
> get LVM resources and dovecot server running in top of them.
> 
> 	The problem I have is that whenever I interrupt network traffic
> between 
> my nodes (to check if quorum and fencing is working) the IP resource is 
> started in both nodes of the cluster.
> 
> 	So it seems that node fencing configure at cluster.conf is not
> working 
> for me. Then I have tried to configure as a stonith resource (since it 
> is listed by sudo crm ra list stonith), so I have tried to include
> 
> primitive stonith_fence_scsi stonith:redhat/fence_scsi
> 
> 	The problem I'm having with this is that I don't know how to
> indicate 
> params for the resource (I have tried params devices="...", params -d 
> ..., but they are not accepted) and with this (default) configuration I get:
> 
> pr 24 14:39:14 myotis51 lrmd: [6759]: debug: on_msg_perform_op: add an 
> operation operation monitor[5] on stonith_fence_scsi for client 6763, 
> its parameters: crm_feature_set=[3.0.5] CRM_meta_timeout=[20000]  to the 
> operation list.
> Apr 24 14:39:14 myotis51 lrmd: [6759]: info: rsc:stonith_fence_scsi 
> probe[5] (pid 10434)
> Apr 24 14:39:14 myotis51 lrmd: [10434]: ERROR: get_stonith_provider: No 
> such device: redhat/fence_scsi
> Apr 24 14:39:14 myotis51 lrm-stonith: [10434]: ERROR: execra: No such 
> legacy stonith device: redhat/fence_scsi
> Apr 24 14:39:14 myotis51 lrm-stonith: [10434]: debug: execra: 
> stonith_fence_scsi_monitor returned -12
> Apr 24 14:39:14 myotis51 lrmd: [6759]: WARN: Managed 
> stonith_fence_scsi:monitor process 10434 exited with return code 7.
> Apr 24 14:39:14 myotis51 lrmd: [6759]: info: operation monitor[5] on 
> stonith_fence_scsi for client 6763: pid 10434 exited with return code 7
> Apr 24 14:39:14 myotis51 crmd: [6763]: debug: create_operation_update: 
> do_update_resource: Updating resouce stonith_fence_scsi after complete 
> monitor op (interval=0)
> Apr 24 14:39:14 myotis51 crmd: [6763]: info: process_lrm_event: LRM 
> operation stonith_fence_scsi_monitor_0 (call=5, rc=7, cib-update=57, 
> confirmed=true) not running
> 
> 	I'm trying to use fence_scsi because I'm planning to use a shared 
> storage (accesed via scsi fibre channel) and I don't want to use CLVM 
> (because I need lvm snapshots, not supported by clvm), so I need a 
> fencing device avoiding to concurrently use the same scsi devices in 
> both nodes.
> 
> 	Any idea on how to use fence_scsi? Or I could use any other 
> fence/stonith device? Which one do you recommend?
> 
> -- 
> Angel L. Mateo Martínez
> Sección de Telemática
> Área de Tecnologías de la Información
> y las Comunicaciones Aplicadas (ATICA)
> http://www.um.es/atica
> Tfo: 868889150
> Fax: 868888337
> 
> 
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