I have recently received several Linux SUN Blades. These all have dual port HBA's but only one port is being used. I would like to know how to use both ports to transfer data between server and McData 4500 SAN switch which in turn goes to an Hitachi Data System 9960. I have not had any training in Linux but have used Solaris for 20 years. Help.

Dual ported fibre cards I'm assuming? (HBA can be anything, SCSI, Ethernet, Fibre, Sound, Video, etc... HBA = Host Bus Adapater).

If so what make/model?

Have you checked the manufacurers web site?

Qlogic for example has quite a bit of information for Linux. You do have to be sure to install the drivers for their cards and possibly flash the bios for compatibility (they even breakdown their information by vendor).

I've successfully used QLogic QLA 2340s in RedHat AS 3.

You may have to update /etc/modules.conf to tell it to use the other ports.

For example for my QLA 2340s (single ports) I have the following entries:

options scsi_mod max_scsi_luns=255 scsi_allow_ghost_devices=1
alias scsi_hostadapter aic7xxx
alias scsi_hostadapter1 megaraid2
alias scsi_hostadapter2 megaraid2
alias scsi_hostadapter3 qla2300
alias scsi_hostadapter4 qla2300

Note the above are for 3 different kind of HBAs (or motherboard) SCSI related controllers (including Fibre) which are:
Adapatec (aic...), Dell PERC (megaraid) and finally the QLA 2340s (qla2300).
If you have 2 dual ported cards it may be you need to have 4 aliases as it may be seen as 4 host scsi_hostadapters so far as modules.conf is concerned.

Looking at the directories beneath /proc/scsi may help. There should be one their that relates to you fibre card.