Subject: Re: UDMA downgrading
To: None <current-users@netbsd.org>
From: Thomas Hertz <thomas@hz.se>
List: current-users
Date: 10/15/2003 21:16:53
I really hadn't read that part of the ATA specs (and none of the other
parts I must admit *ahem*), but it didn't help putting the disks in the
end of the cables either. =(
The cables are the ones that came with the Promise cards, and they seem
to be of good quality. I don't think that my server chassi is any
"noisier" than any other chassi, so it seems like I'm stuck here.
--
Thomas Hertz
Charles M. Hannum wrote:
>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.
>
>