SAN use to store data from all server
Using an NFS-served Ext3 file system, or GFS you will able to deploy large pools of shared storage that can be accessed by multiple server or servers in cluster.
Three steps to attach SAN to Linux boxes
a) Configuring the fibre HBA (Host Bus Adapter)
b) Configuring the udev service to find the SAN Volume(
c) Configuring the fstab entries to mount the SAN Volume(
Run following command to configure RHEL cluster
Code:
redhat-config-cluster
It is not that hard. I recommend reading all docs loaded here
http://www.redhat.com/docs/manuals/csgfs/