[ale] SCSI Underflow Error?

[David S. Jackson]

Hi, 

I occasionally get the following type of error from my internal scsi
zipdrive which is connected to my Adaptec 2940UW:

<quote>

(scsi0:2:0) Underflow - Wanted at least 33792, got 29696, residual SG count 3.
(scsi0:2:0) Underflow - Wanted at least 33792, got 29696, residual SG count 3.
scsi0 channel 0 : resetting for second half of retries.
SCSI bus is being reset for host 0 channel 0.
(scsi0:-1:0) Reset device, active_scb 3
scsi0: Resetting current channel A
scsi0: Channel reset, sequencer restarted
scsi0: Target 2, channel A, refusing synchronous negotiation; using asynchronous transfers.
(scsi0:2:0) Underflow - Wanted at least 33792, got 29696, residual SG count 3.
(scsi0:2:0) Underflow - Wanted at least 33792, got 29696, residual SG count 3.
scsi0: MEDIUM ERROR on channel 0, id 2, lun 0, CDB: Read (6) 02 fa b8 42 00 
Current error sd08:14: sense key Medium Error
Additional sense indicates Data synchronization mark error
scsidisk I/O error: dev 08:14, sector 195284, absolute sector 195316

</quote>

The /etc/fstab line is:

/dev/sdb4                 /mnt/zipdrive             ext2   defaults 1 2

The error above was on a reboot.  I had gotten errors similar to this during
a badblock check on /dev/sdb4.  The drive started clattering and my xconsole
issued a bunch of errors, and then it looked like a kernel panic (though it
didn't say so) because all input devices seemed to be ignored. No keyboard
input was accepted, no mouse input, the zipdrive and scsi cdrom were ignored
as far as the system acknowledging them, and the screen was frozen.  Telnet
attempts were not acknowledged (no login prompts).  This was the first time
I thought I had to press the reset button in my three years of using Linux.
I couldn't think of anything else to try.  (SCSI is pretty foreign ground to
me.)

Can anyone tell me where to check from here?  

BTW, I normally mount my zipdrives as ext2fs after formatting them thusly.
On bootup, I got the following error during initialization:  

<error>

Jul 22 23:06:13 sylvester kernel: scsi0: Target 2, channel A, refusing synchrono
us negotiation; using asynchronous transfers.
Jul 22 23:06:13 sylvester kernel:   Vendor: IOMEGA    Model: ZIP 100           R
ev: E.08
Jul 22 23:06:13 sylvester kernel:   Type:   Direct-Access                      A
NSI SCSI revision: 02
Jul 22 23:06:13 sylvester kernel: Detected scsi removable disk sdb at scsi0, cha
nnel 0, id 2, lun 0

</error>

Is this relevant?

--
David S. Jackson                           http://www.dsj.net
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