[Pc_Support] Re: Any recommendations on U160 SCSI RAID cards?

[Bryan J. Smith <b.j.smith at ieee.org>]

From: Jason Boxman <jasonb at edseek.com>
> I might be in the market for a Linux friendly SCSI RAID controller for a RAID 
> 5 array of 4 Seagate Cheetah drives.  Anyone have any recommendations?

New or used?

If used, then there are plenty of Mylex eXtremeRAID 1100/2000 cards that
are about 5 years old, but still very powerful StrongARM SA110 206MHz
Ultra80/Ultra160 2-3 channel cards with 64MB SDRAM or so for maybe
$100-250.  They will roast and toast anything i960-based.

If new, then anything LSI MegaRAID SCSI "X" -- meaning 400MHz+
Intel XScale (Superscalar StrongARM), like the SCSI 320-2X for PCI-X
or maybe even the 320-2E for PCIe x8.  The latter can go in an SLI
mainboard (one PCIe x8 channel for video, the other for the card),
or any mainboard that has a good PCIe x4 or x8 slot if you're trying
to avoid costs (although the board is $500, the commodity mainboard,
CPU and DDR SDRAM will give you a good "bang for the buck").

> Good RAID 5 performance is key.  If it has two ports, bonus, because
> I'll run another 2 Cheetahs in RAID 1 for the OS partitions.

Actually, when it comes to SCSI channels, you should typically span
drives of the _same_ volume over _multiple_ channels.  I.e., 4 drives
with 2 channels means you should have 2 drives on each channel,
even (and especially) if they are in the same volume.

> (The existing controller only has a single connector and is 
> quite old.  16MB of RAM for RAID 5 is painful.)

Most everything is going to be 128MB+ these days.  Maybe older
solutions might only be 64MB.

But don't bother with anything i960/IOP30x-based.  At least go
for a XScale/IOP33x, or possibly an older, used SA110-based.



--
Bryan J. Smith   mailto:b.j.smith at ieee.org