Subject: Re: Many PCI IDE cards in one box, is this possible?
To: Manuel Bouyer <bouyer@antioche.lip6.fr>
From: Brian Buhrow <buhrow@lothlorien.nfbcal.org>
List: port-i386
Date: 01/19/2001 12:20:58
	We have Promise Ultra/100 cards in the unit right now.
-Brian
On Jan 20,  2:58am, Manuel Bouyer wrote:
} Subject: Re: Many PCI IDE cards in one box, is this possible?
} On Fri, Jan 19, 2001 at 05:56:34AM -0800, Brian Buhrow wrote:
} > 	Actually, I put 11 drives in a single raid 5 array, and 
} > made the 12th drive a hot spare.  The parity calculation seems to take
} > about
} > 24 hours, and while it's running, it takes a half hour to login.  This is
} > on an Intel motherboard with a 733MHZ cpu and 256MB of memory.  I'm hoping
} > this is just the pain of initialization, but if it keeps up this way, I
} > don't know how useful it will be.  We're currently waiting for the second
} > attempt at parity initialization to complete.  I've also been making the
} > stripe size smaller in an effort to lower the per disk i/o request size to
} > keep individual i/o errors from the too long IDE cables from spoiling the
} > party.  So far, so good.  Unfortunately, Manuel says that the limit for
} > UDMA100 cables is 18 inches.  Our cables are 24 inches, and we have no
} > physical way of shortening the cables and reasonably installing these disks
} > in a box compatible with the cooling requirements to run so many disks.
} > So, other than living with the slower disk performance with these  longer
} > cables, is there anything we can do?
} 
} Try to force the drives to use Ultra/33 (with 'flags 0xa00' on the
} wd* line in your kernel config file).
} What controllers do you have ?
} 
} --
} Manuel Bouyer, LIP6, Universite Paris VI.           Manuel.Bouyer@lip6.fr
} --
>-- End of excerpt from Manuel Bouyer