UNIX for Dummies Questions & Answers

Hello UNIX Experts.
I am responsible for our company's LAN and Clariion SAN environments. My primary responsibilities have always been on the Windows server side for disk on the SAN. I no nothing about UNIX. I think it might be a rock group.?
I am now being asked to provide a new disk/LUN on our Clariion, which houses all UNIX host data as well. The disk is going to provide adequate sizing for what I am told is the UNIX "swap space". I have no idea what this "swap space" acts like or does, and I would appreciate an explanation so that I can create an appropriate LUN.
On the Clariion, my options include choosing a separate bus, enclosure and physical disk drives which I might do anyway, but should I choose RAID 1 or RAID5?
In addition, what about providing this "swap space" LUN on a completely separate fiber channel adapter in the UNIX host? Will that accomplish anything? The bottom line is, I don't want to make things worse. I want to know what I am doing and why, and provide the best configuration possible to the UNIX admin.

Kurt

Swap space is like in Windows your RAM on hard disks where stuff that normally resides in your RAM is swapped/paged out so it is not lost. Needless to say, that this is many times slower than getting your data from RAM.
For you as Clariion admin you should take Raid 1, which is a bit faster than Raid 5 and absoluteley sufficient. If the box crashes, everything is in swap space is useless after a reboot anyways afaik.
If a Unix/Linux box and also a Windows box starts to swap, there is either a bad tuned system or just too few RAM, so it doesn't matter that much, how much effort you put in creating the fastest swap space you can provide with separate FC adapters etc.

Short version - if a box starts to swap, it's performance is degrading very bad and it will need tuning or more physical RAM. A fast or big swap space on disk is usually not as fast as real RAM.

Nevertheless, you just bind a LUN, Raid 1 as usual, assign it to a storage group as usualy and have you LUN masking with Access Logix, that's all. The Unix host will see new physical volume and the swap space can be created on it.

I hope this helped a bit.

Thank you for taking the time to reply. Your response is one of many that have helped us make the case to purchase RAM for our system.

Kurt.