Re: PROBLEM: Kernel 2.2.0 destroyed filesystem

Richard Fish (rjf@estinc.com)
Wed, 27 Jan 1999 09:16:30 -0700

Vladimir Dergachev wrote:
>
> I think this is a result of improper UDMA on your system (it got
> introduced right after 2.0.34). You have to disable it - look
> in kernel documentation and also the flag ENABLE_DEFAULT_DMA or something
> similar. Basically data is getting corrupted on the way from controller to
> drive - not good at all.
>
> For test try to mount you system readonly from floppy and running hdparm
> to turn DMA flag on and off.

> On Wed, 27 Jan 1999, Antti Sinisalo wrote:
> > Seagate ST36531A Medalist 6531 IDE hard disk

Hmm, I think this is actually a Medalist Pro 7200rpm drive. If so, DMA
is almost certainly the problem. I've discovered after MUCH pain that
to use DMA with my ST36530A I have to keep the cable length under
14-inches. Note that this is probably a shortcoming of the drive, as I
have other UDMA drives running off 18-inch cables with no problems at
all.

-- 
Richard Fish                      Enhanced Software Technologies, Inc.
Software Developer                4014 E Broadway Rd Suite 405
rjf@estinc.com                    Phoenix, AZ  85040 
(602) 470-1115                    http://www.estinc.com


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