[svlug] IDE RAID versus BOD SCSI -- Re: 3ware IDE RAID Recommendation ...

Bryan -TheBS- Smith thebs at theseus.com
Tue May 30 13:15:08 PDT 2000


IDE RAID versus BOD SCSI -- Re: 3ware IDE RAID Recommendation ...

> TheBS> *OTHERWISE*, I *HIGHLY RECOMMEND* those 3ware cards
> TheBS> (http://www.3ware.com).  

On Tue, 30 May 2000, Rick Moen wrote:
> IDE raid?  No thanks.
> 
> About the only point of that would be maximum storage with redundancy
> per dollar, with all other considerations including real-world
> performance and IRQ consumption, taking a back seat.  I value my time
> and trouble, and therefore buy only quality hardware.

If you are talking software-based IDE, I ***TOTALLY AGREE WITH
YOU***.  Figuring 20-25% CPU utilization per disk, it's going to
get nasty very fast.  So, I limit software-based IDE to either a
2-day RAID-0 (striping, for workstation speed) or RAID-1
(mirroring, for simple redunancy).

Now getting to hardware, the situation may or may not be different.
 Promise's RAID controllers are NOTHING MORE THAN A SINGLE
CONTROLLER.  The Ultra66 and FastTrak66 are NO DIFFERENT, except
for firmware.

*BUT*, 3ware makes some excellent co-processed RAID controllers. 
One-channel per drive, a i960 (I believe) on-board to off-load the
CPU, and FULL SCSI COMMAND-TAG QUEUING (even in the Linux driver)
-- a major key to performance (whereas the Promise cards are NO
FASTER than software RAID in NT or Linux).  This translates into a
very cheap and efficient RAID solution (not to mention the LACK of
headaches that come with software RAID).

Case-in-point, using a 3ware solution will give you a higher
performance, more redundancy (assuming you use RAID-0+1) at a lower
cost than plain SCSI disks.  Will it replaced SCSI RAID?!?!?!  HELL
NO!  But it makes the best, low-cost solution (*UN*like the Promise
cards) when you can't afford SCSI RAID.

-- TheBS

P.S.  At $110 for a 2-channel, co-processed board, I'll recommend
the 3ware solution.

-- 
 Bryan "TheBS" Smith -- Engineer, IT Professional and Hacker
      E-mail:  mailto:thebs at theseus.com,b.j.smith at ieee.org
  Disclaimer:  http://www.SmithConcepts.com/legal.html
*************************************************************
  TheBS ... Serving E-mail filters to /dev/null since 1989






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