On Thu, Apr 19, 2001 at 09:59:11AM -0400, Jon Lindgren wrote:
> On Thu, 19 Apr 2001, Diana Eichert wrote:
> 
> > Speaking of IDE, the 3ware RAID card is an intersting alternative using
> > IDE.
> 
> Absolutely.  Does anyone who has used one have comments about it?  I'm
> particularly concerned about the cable length issue... I still can't see
> fitting 6 drives in a case _easily_, but I suppose it could be hacked
> somehow.

Yup, I've got the 4 drive version of the 3Ware Escalade (3W-6400).

I compared an Adaptec 2100S with 2 x IBM LVD drives (DNES-18GB)
RAID1 vs the 3ware 3W-6400, with various combinations of 2, 3,
and 4 IBM 30GB ATA100 drives (DTLA-30GB) running RAID1, RAID0, RAID5
and RAID1+0 (4 drives, a mirrored pair striped to another mirrored pair)

In short, the 4 drive RAID1+0 on the escalade was the fastest in
transactions and much faster in `stupid raw dd throughput', but in all
other cases, the scsi was faster in transactions but slower in raw
throughput (I think Andrew Doren is still improving the performance on
the 2100S driver).

My gut feel is that if you can afford it, stick with LVD SCSI and a
hardware RAID card, because of the simplicity of cabling, and the card
is a bit better about funky stuff like drive replacement. Also, the
higher end cards support battery backed up write cache. SCSI has the
advantage that it supports stuff like bad block mapping, which AFAICT
IDE doesn't (I got a bad block in an IDE disk under raidframe; time to
rip the drive out and send it back under warrenty)

For a home system or small server, however, I think you can't go wrong
with the 2 device Escalade to mirror 2 drives, or the 4 drive version
to do RAID1+0 (RAID1 mirror then RAID0 stripe the mirrors), especially
if you put the drives in hot-plug ide carriers (which cost ~ U$15 here
in Australia).

I should whip up report on my experiences with scsi raidframe, ide
raidframe, scsi h/w raid and ide h/w raid. i'll add that to my todo,
after a bunch of work related stuff and my freenix paper.

Luke.