[Linux-cluster] Shared Storage and Quorum device

[Mikhail A Zelikov]

I was wondering if anybody has information on this. I have 2 node cluster
and some shared storage between two nodes.
The manual contains some information on the shared storage setup:
http://www.redhat.com/docs/manuals/csgfs/browse/rh-cs-en/s1-hardware-cluster.html#S2-HARDWARE-STORAGESETUP
Section 2.5.3.1 at
http://www.redhat.com/docs/manuals/csgfs/browse/rh-cs-en/s1-hardware-connect.html.
However I could not find a way to tell the cluster to use my raw devices
and also test that any of these devices are being used. I also use my
cluster w/o any shared devices and it seems to work.
But in this case a 2-node cluster requires a quorum devices (usually
shared storage) - I can see that when one node is down I still have a
quorum w/o using any shared storage.

So my questions are:
1. Do I have to have a shared storage?
1.a If yes then how do I configure and test it?
1.b If no then how is the quorum is achieved in 2-node cluster when 1 node
is down?

Thanks,
Mike