[Pacemaker] Split brain and STONITH behavior (VMware fencing)

[Andrei Borzenkov]

On Wed, Oct 29, 2014 at 10:46 AM, Ariel S <ariel_bis2030 at yahoo.co.id> wrote:
> Hello,
>
> I'm trying to understand how this STONITH works.
>
> I have 2 VMware VMs (moon1a, moon1b) on two different hosts. Each have 2 nic
> assigned: eth0 for heartbeat while eth1 used for everything else.
>
> This is my testing configuration:
>
>     node $id="168428034" moon1a
>     node $id="168428035" moon1b
>     primitive Foo ocf:heartbeat:Dummy
>     primitive stonith_moon1a stonith:fence_vmware_soap \
>             params ipaddr="192.168.1.134" login="foo" \
>                     uuid="42053b22-d3fd-25fe-6fb3-7cb2c7cd2c63" \
>                     action="off" verbose="true" passwd="bar" \
>                     ssl="true" \
>             op monitor interval="60s"
>     primitive stonith_moon1b stonith:fence_vmware_soap \
>             params ipaddr="192.168.1.134" login="foo" \
>                     uuid="4205b986-4426-5de4-1069-b10a77123bc4" \
>                     action="off" verbose="true" passwd="bar" \
>                     ssl="true" \
>             op monitor interval="60s"
>     clone FooClones Foo
>     location loc_stonith_moon1a stonith_moon1a -inf: moon1a
>     location loc_stonith_moon1b stonith_moon1b -inf: moon1b
>     property $id="cib-bootstrap-options" \
>             dc-version="1.1.10-42f2063" \
>             cluster-infrastructure="corosync" \
>             stonith-enabled="true" \
>             last-lrm-refresh="1414565715"
>     rsc_defaults $id="rsc-options" \
>             resource-stickiness="200"
>
>
> The vCenter is at 192.168.1.134 and the uuids taken from a list generated by
> fence_vmware_soap.
>
> When I do fencing manually using:
>
>     # fence_vmware_soap -z -a 192.168.1.134 \
>                         -l foo -p bar \
>                         -U 4205b986-4426-5de4-1069-b10a77123bc4 \
>                         -o off
>
> from moon1a, as expected the moon1b (4205b986-4426-5de4-1069-b10a77123bc4)
> VM
> died, so the configuration should be right, I think.
>
> But so far I cant emulate split brain by killing corosync like this:
>
>     # killall -9 corosync
>

Killing corosync is not strictly speaking split-brain, it is emulation
of (partial) node failure.

>
> My questions:
>
>     1.    Is my configuration correct?

On two node cluster you also need no-quorum-policy=ignore, otherwise
remaining node won't initiate fencing.

>     2.    How one cause a split-brain to trigger the expected stonith
> behavior?
>
>
>
> Thank you,
> Ariel
>
>
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