Re: Problems with DMA on IDE/ServerWorks/Seagate.

[Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>]

On Thursday 15 of July 2004 02:16, Dave Woods wrote:
> Please CC me on all replies, as I am not subscribed to the list.
>
> We have diagnosed a problem (file corruption) using Ultra DMA & IDE with
>
> ServerWorks OSB4 Chipset and Seagate drives under heavy disk I/O.
> We were able to find a thread that discusses this problem in detail,
> but dates back to 2001. We have nearly 100 boxes using this
> configuration
> with kernal 2.4.20, and we can reproduce the problem easily with a perl
> script using md5 checksums.
>
> The applicable thread is given below:
> http://www.uwsg.iu.edu/hypermail/linux/kernel/0109.3/1006.html
>
> We've disabled DMA on several machines, and that appears to fix
> the problem. However, despite seeing this workaround mentioned
> several times, we have not had any luck downshifting to mdma2.
> Every time I attempt it, all disk accesses freeze up, and the box
> has to be rebooted.
>
> Our question: short of disabling DMA on all of our machines, what
> other alternatives are there? I've played with using the hdparm -p
> parameter prior to issuing hdparm -X34 and hdparm -d1, but it
> doesn't like it. Is there a simple fix to this problem out there?

Upgrade to 2.4.26 and see if it fixes your problem.