We are setting up a cluster for a storage application with SAN disks managed through HA-LVM and connected through multipath. There are actually two applications which have to run on the same node, but only one of them needs the disk. Both of them have clients.
The question I have is what should happen when the SAN fails: Should both applications failover to another machine (possibly after a retry) or should the application which doesn't need the disk keep running while the other is shut down? I'm not sure how much recovery can come out of a failover in case of a SAN failure, if it's not both network cards of the node which are defective or whatever.