[Pacemaker] quorum disk

[jimbob palmer]

2010/2/8 Andrew Beekhof <andrew at beekhof.net>:
> On Mon, Feb 8, 2010 at 4:36 PM, jimbob palmer <jimbobpalmer at gmail.com> wrote:
>>>>> I've searched the mailing lists for qdisk, quorum disk and quorum
>>>>> partition but found nothing.
>>>>>
>>>>> How can I configure a two node cluster to use
>>>>
>>>> a quorum disk so that the node that can see the disk will keep resources?
>>>
>>> We dont have support for qdisk.
>>> Check out no-quorum-policy instead.
>>
>> I can't find much documentation for no-quorum-policy. I need the
>> cluster to keep working in case the connections between the two
>> datacenters are cut. It should be impossible (or very nearly
>> impossible) for both sides to have the clustered resource up. This is
>> for a drbd+nfs+ip setup.
>>
>> no-quorum-policy doesn't seem to help with the split brain situation does it?
>
> No, but I can't imagine qdisk does either.
> Do you at least have fencing?

Fencing wouldn't give me an advantage because the physical path to the
second datacenter is not separate for networking and san. In the event
of a cut, the primary site needs to win.

>>> Alternatively, you could create a scsi-reservation resource and
>>> colocate your other resources with that (aka. a resource driven
>>> cluster)

This sounds good, so all resources have a parent resource which has
the ability to get a scsi reservation?

Where can I find out about this? I can see a resource called
scsi2reservation but it mentions an out-of-distro package called
scsires. It would be good if I could use sg_persist instead.

Am I going in the right direction?

>>
>> Is this like ocfs2? Each node locks a journal, and if it can't lock
>> the journal its kernel panics?
>
> No, it just prevents the resources that depend on the scsi lock from
> running if it can't get the lock .
>
>> Leaving the cluster would be better
>> here. Where can I read about this?
>
> This is a good start on the concept:
>   http://devresources.linux-foundation.org/dev/clusters/docs/ResourceDrivenClusters.pdf

Thanks for this. Any more configuration-related documentation you can
throw at me would be good :)