From mboxrd@z Thu Jan  1 00:00:00 1970
Message-Id: <200007172103.RAA17759@smtp4.fas.harvard.edu>
To: 9fans@cse.psu.edu, Axel.Belinfante@cs.utwente.nl
Subject: Re: [9fans] dossrv: I/O error: dev 3 sector ..., read: 0, should be 4608
From: "Russ Cox" <rsc@plan9.bell-labs.com>
Date: Mon, 17 Jul 2000 17:03:35 -0400
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The first thing to do is see if the sector
numbers make any sense.  First,
multiply them by 512 and see if they're
still 31-bit numbers.  If not, you need
to change devio.c thusly:

g% diff /n/dump/2000/0601/sys/src/cmd/dossrv/devio.c devio.c
38c38
< 	seek(xf->dev, xf->offset+addr*Sectorsize, 0);
---
> 	seek(xf->dev, xf->offset+(vlong)addr*Sectorsize, 0);
57c57
< 	seek(xf->dev, xf->offset+addr*Sectorsize, 0);
---
> 	seek(xf->dev, xf->offset+(vlong)addr*Sectorsize, 0);
g%

If that's not the problem, make sure you
actually can read from those sectors:

dd -if /dev/sdC0/dos -bs 512 -count 9 -iseek sectornumber >/dev/null

Russ