Subject: Re: UDMA downgrading
To: Thomas Hertz <thomas@hz.se>
From: Charles M. Hannum <abuse@spamalicious.com>
List: current-users
Date: 10/15/2003 18:33:42
On Wednesday 15 October 2003 06:14 pm, Thomas Hertz wrote:
> What is the problem here? I've gotten all kinds of suggestions from a
> bad mainboard to bad disks, but none of them seem likely. Would it be
> better if I would put the disks in the end of the IDE cables instead of
> the middle one? Is somehow raidframe to blame here? I'm confused.

I think you may have answered your own question.  If you have one drive on the 
cable, and it's running in UDMA, it MUST be at the end of the cable.  If it's 
not, the signal will not be stable (you basically have a big antenna hanging 
off the drive).  This is documented in the ATA spec.

You're more likely to lose in the RAID array because you're more likely to 
have all of the drives active at once, and therefore have maximal 
interference.