[Beowulf] RAID storage: Vendor vs. parts

[Steve Cousins]

On Tue, 22 Feb 2005, Alvin Oga wrote:

> hi ya steve
> 
> On Tue, 22 Feb 2005, Steve Cousins wrote:
> 
> >> I'm in the process of getting a couple 16 Bay 6.4 TB RAID units.  The
> >> vendors who have given me quotes have a SATA-SCSI version for around
> >> $14,000 each.  I can get a similarly equipped StorCase unit for around
> >> $11,000. With the StorCase I envision that I'd be more on my own if
> >> anything went wrong.  However, with the cheaper price, I'd be able to buy
> >> a spare RAID controller to have on hand in case one of them failed and
> >> still save a couple grand.
> >
> let's say $300 for 300GB (sata) disks ==> $4,800 for 16 disks ...
> 	- pata disk is $150-$200 for 300GB disks
> 
> 	- i'd put 2 or 3 raid controllers in it instead of 1 ..
> 	unless there is an absolute requirement that there is only
> 	1 disk subsystem that has the capacity of 6TB on "one disk"

That's what I'm shooting for. Anybody have good luck with volumes greater
than 2 TB with Linux?  I think LSI SCSI cards are needed (?) and the 2.6
Kernel is needed with CONFIG_LBD=y.  Any hints or notes about doing this
would be greatly appreciated.  Google has not been much of a friend on
this unfortunatlely. I'm guessing I'd run into NFS limits too.

Also, am I being overly cautious about having a spare RAID controller on
hand?  How frequent do RAID controllers go bad compared to disks, power
supplies and fan modules?  I'd guess that it would be very infrequent.
Looking back at my own experience I think I've had to return one out of 15
in the last eight years, and that was bad as soon as I bought it.

If this is too off-topic let me know and I'll move it elsewhere.

Thanks,

Steve