Chris R. Brown wrote:
> I've just come back to my RAID project and have run into some
> more problems. I was wondering if anyone on the list has kludged
> three promise ultra 33 cards and one onboard IDE controller together
> in one box. I'm still trying to get a big (128 gig) array going, but
> it isn't working.
The current IDE code, including the latest udma unified drivers, only
supports a max of three cards and 6 total interfaces. I talked with Andre,
the linux UDMA guy, once about this limit... he said he could easily up it,
but "what would be the point?".
So if you're really stuck on doing this, he'd be the man to talk to. It
definitely won't work without code changes. I have three promise cards
installed + my onboard, and I have to a) disable the onboard in the BIOS and
b) boot with ide0 and ide1 kernel boot parameters to prevent the onboard
(already disabled) from still being detected and being set up first. If
this happened my last interfaces (ide6 & ide7) never show up and are
unavailable.
If you haven't yet fully built this system, I wish to caution you. I built
an inexpensive ide raid system last fall using these components (10 x 8.4g
udma maxtor drives) with three promise controllers. My biggest problem has
been the average quality and lifespan of ide drives (i've replaced 3!!) and
the maximum cable length of ide drives. It is VERY, VERY hard to place 12
drives (I have two 4 gigs for raid boot/root) inside a case and stay under
the 18" ide cable restriction!! Many, many cables are sold that are longer
than this maximum 18" cable, but these cables can and will cause errors
under udma under linux. I ended up spending many, many late nights trying to
diagnose cable/drive/enclosure problems with this system. If I had it to do
again, I might very well see if there was a small country bank nearby to
knock over... thus allowing me to buy scsi. I think it would be less stress
;)
Take care,
Tom
