Subject: Re: scsi errors writing an ffs filesystem on a ZIP disk
To: None <explorer@flame.org>
From: Roland McGrath <roland@frob.com>
List: current-users
Date: 12/08/1995 21:16:35
   cc: current-users@netbsd.org, port-i386@netbsd.org
   Date: Fri, 08 Dec 1995 19:40:43 -0600
   From: "Michael Graff" <explorer@flame.org>


   My guess (and this is just a guess) is that you have bad termination,
   a bad cable, or both.  The DOS and Winblows drivers do plenty of
   silent retries.  NetBSD doesn't do this.

   >I can write, but when I write sizable amounts, I get lots of message like this
   :
   >
   >sd1(uha0:5:0): non-media hardware failure, data = 00 00 00 00 47 00 00 00 00 0
   0 0b 02 01 0a 30 00 00

   >What is really odd is that no matter how much I write, I cannot get
   >this problem to happen with the MSDOS filesystem.

   Is that still under NetBSD?  If so, that's odd, since it is a
   low-level sort of error...

Yes, sorry that was not clear.  If I mount an MSDOS-format ZIP disk on
the same netbsd kernel (no rebooting or anything), it works fine.

I exercised such a disk a fair bit and could not produce the errors.
The cases I tried on the MSDOS filesystem for an hour produced errors
in five seconds on the ffs filesystem.

   >Can anyone perform that test case successfully on their ZIP drive?

   Every day...

What SCSI controller do you have?