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Notes on configuring HBA fibre channel cards
SANSurfer
SANSurfer permits to configure the qla2xxx_conf module, which does failover & multipathing.
It even asks to activate the failover during install process and edits "/etc/hba.conf".
Default password is "config".
It is able to upgrade the bios.
The firmware gets updated by operating system's driver. Either during driver's install or each time at boot, during HBA's initialization (which one is it ? mail at foot). Drivers need specific firmware versions.
Note. it's ok to have a more recent bios than firmware, but not the contrary !
Multipathing
Beside SANSurfer's failover capability (vi /etc/hba.conf), you may also need more. Therefore it's preferable to deactivate SANSurfer's failover capability (or don't install SANSurfer at all) and use one of these:
Linux distros' tools (e.g. for EMC bays)
device-mapper-multipath (Redhat)
multipath-tools (Novell)
Note old method's equivalent was using md raid device on both pathes, treating one path as spare,
mdadm --create -f -lmp -n2 -x1 /dev/md0 /dev/<channela> /dev/<channelb>
Against IBM DS4000 bays, RDAC is prefered. Against IBM DS9000 bays, sdd is prefered, sdd (failover & load balancing) for IBM ESS, DS600 DS8000.
Modules
qla2xxx_conf as for multipathing
qla2xxx for the HBA
qla2300 or qla2400 for the firmware-loader (does this actually updates the firmware ?)
References
One caveat, if you're not running with write cache mirroring on you your
volumes, then no matter md or qla failover, you may get data corruption.
Some apps don't run well with it on because of the performance hit.