Subject: wd.c crashes/hard errors
To: None <>
From: Dirk Steinberg <>
List: current-users
Date: 02/09/1994 13:50:33

yesterday it happened again: I was running a current-940207 system &
kernel. I have a Quantum LPS 240 AT hard disk and since this one had
problems with the -current wd.c, I doubled the WDCNDELAY (all this is
from memory, for reasons that will become apparent soon) value (this
was suggested some time ago on this list. So during normal operation,
suddenly the kernel hung with repeated messages like this:

wdc0: busy too long, resetting
wdc0: busy too long, resetting
wdc0: busy too long, resetting

As a side note, I am observing extra interrupts every so often. I
always get one directly after (or maybe during?) the autoconfig phase:

wdc0: extra interrupt

I already had these types of crashes before, and every time a
filesystem was damaged so badly that fsck couldn't repair it. This
time it was the root filesystem...

Even worse, when checking the fs after reboot, fsck hangs the system

wd0a: hard error reading fsbn 10720 of 10720-10723

This error is persistent across reboots, power off, etc. Now since I
have a IDE disk I shoudn't get hard errors. I never had any hard
errors before, and my Linux partition still works fine. So my NetBSD
installation is hosed for now. I sure hope this error goes away when I
reinstall/re-mkfs. Is it actually possible that the faulty wd.c caused
damage to my disk, or that it at least screwed up the low-level format
on some track? If so, how could I reformat a single track without
reformatting the entire disk? And how to format (low-level) a IDE disk
in the first place? I know how it works for MFM/RLL/ESDI and SCSI
disks and have done this many times before. But IDE disks?

Any comments or hints welcome,



PS: This makes 3 completely lost ufs filesystems in 3 weeks. I have
    never lost any ext2 filessytem in 2 years. I have never seen a
    complete filesystem disappear like this on my Sun or any Sun at
    work. So much for stability (at least for IDE drives)...

PPS: I never had any problems, lost or extra interrupts, controller
     resets or anything with this hardware under Linux.

Dirk W. Steinberg - RWTH Aachen - Internet email:
Aachen University of Technology / IS2-Integrated Systems in Signal Processing
Rhein.Westf.Tech.Hochsch. Aachen / Integrierte Systeme der Signalverarbeitung
Templergraben 55 / D-52056 Aachen / phone:+49 241 807879 / fax:+49 241 807631
Home address: Kleikstr. 63, D-52134 Herzogenrath,Germany/phone: +49 2406 7225