[1049] in linux-scsi channel archive
Re: scsi 2940 controllers
daemon@ATHENA.MIT.EDU (Steve Brueggeman)
Sat Nov 30 20:54:27 1996
To: submit-linux-dev-scsi@ratatosk.yggdrasil.com
From: stevebr@primenet.com (Steve Brueggeman)
Date: 30 Nov 1996 18:50:02 -0700
On Sun, 3 Nov 1996 19:40:06 +0000 (GMT), Gerard Roudier
<groudier@club-internet.fr> wrote:
>
>
>On Sun, 3 Nov 1996, Matthias Urlichs wrote:
>
>> In linux.dev.scsi, article <2.2.32.19961028192441.00693f04@mail.bluesky.net.au>,
>> tommiy <tommiy@bluesky.net.au> writes:
>> > Can anybody please help stop my system from locking up, please. It seems to
>> > be an impossible task.
>> >
>> In fact, it is very easy to do that..:
>>
>> >
>> > scsi0: MEDIUM ERROR on channel 0, id 3, lun 0, CDB: 0x0 a 13 29 c1 f4 00
>>
>> Did you ever look at the error message, and think about what MEDIUM ERROR
>> might actually mean?
>>
>> You just have a bad spot on your hard disk.
>>
>> Now, the fact that the system doesn't recover from the error _is_ a bug, all
>> right, but it's not the source for your problem...
>
>Agreed about the source of the problem, but not about the _Linux_ bug.
>
>For example:
>
>- Unrecoverable read error cannot be recovered by the firmware until you
> do a destructive write to the spot with AWRE enabled (and obviously
> supported).
> Remapping the sector with some famous disk tool is impossible without
> data lost.
> Only user is responsible of lost data.
>
>In the initial post, it was written:
>ASC=10 ASCQ=00 that should mean "ID CRC OR ECC ERROR".
>
A sense code of 03, with ASC=10 ASCQ=00 usually means that the drive
had problems addressing the requested sector group. This is loosely
refered to as an address type error.
I believe that Gerard is correct, in that enabling the AWRE bit in
mode page 01, and then writing to the sector in question should
re-assign this sector, and will also result in loss of data.
But, if the drive is having problems addressing this sector, it'll
probably have problems addressing other sectors too. I would
recommend that a low-level format be done on the drive, as this should
rewrite the sector headers for the whole drive.
You should also consider that this drive might be near it's end too,
in that the heads might be crashing. Unless this is a new drive, in
which case, rough handling, could have bumped the heads enough to
knock them out of their original alignment. If the later is the case
(a new drive), a format 'should' be able to bring your drive back to
usablility. The exception, would be if the heads have been jarred so
far from their factory positions, that the original defect list stored
on the drive, doesn't apply.
Still, if you format the drive, with certificaiton enabled, it should
find the worst of the media defects, and you should still have a
usable drive. You might get occasional sense code 01 errors though,
which would be caused by the weaker defects, that the certification in
the format command did not find.
