HowTo setup a Quorum Disk under Red Hat

[ Thanks to asanabria6910 for this link.
]

“Since if I still have 1 node available, the node
should still be able to use the GFS2 mount. So I did some research
about this quorum disk and what it can do for me. Let me tell you,
this was exactly what I was looking for. 1st let me start out my
explaining what a quorum is ( relating to clustering ). A quorum is
the minimal number of votes that is needed in a cluster, usually
the majority. So if you have 3 nodes in a cluster, that means you
have a total of 3 votes in the cluster and you will need a minimum
of 2 votes to remain in a quorate state. Which means you can lose 1
node in the cluster and the other nodes are still functional. But
if you lose 2 nodes, your quorum will be dissolved. Which means
even though your GFS2 file system is still mounted on your final
node, it will not be accessible to you.

“The quorum disk will help this particular situation… You ask
how???? Well here it is… Qdisk needs at a minimum of a 10MB disk
partition shared across the cluster. Qdiskd runs on each node in
the cluster, periodically checking its own health and then placing
its state information into its assigned portion of the shared disk.
On each node qdiskd then looks at the state of the other nodes in
the cluster as posted in their area of the qdisk partition. When
all the nodes that are running qdiskd are in a healthy state, the
quorum of the cluster is increased by the value of the shared
Quorum Disk.”

Complete
Story