Dominic J Hulewicz wrote:
> 
> This is what I get on bootup:
> 
>   Adaptec AHA-2940 BIOS v1.115

"Me too", though I can't remember the BIOS revision
ahc0: aic7860 Single Channel, SCSI Id=7, 3 SCBs

> office# fdisk /dev/rsd0d
> ******* Working on device /dev/rsd0d *******
> Warning: BIOS sector numbering starts with sector 1
> parameters extracted from in-core disklabel are:
> cylinders=961 heads=32 sectors/track=68 (2176 sectors/cylinder)
> 
> Figures below won't work with BIOS for partitions not in cylinder 1
> parameters to be used for BIOS calculations are:
> cylinders=1037 heads=32 sectors/track=63 (2016 sectors/cylinder)
> 
> Information from DOS bootblock is:
> 0: sysid 0 (unused)
>     start 0, size 0 (0 MB), flag 0x0
>         beg: cylinder    0, head   0, sector  1
>         end: cylinder    0, head   0, sector  0
> 1: sysid 0 (unused)
>     start 0, size 0 (0 MB), flag 0x0
>         beg: cylinder    0, head   0, sector  1
>         end: cylinder    0, head   0, sector  0
> 2: sysid 0 (unused)
>     start 0, size 0 (0 MB), flag 0x0
>         beg: cylinder    0, head   0, sector  1
>         end: cylinder    0, head   0, sector  0
> 3: sysid 165 (NetBSD or FreeBSD or 386BSD)
>     start 63, size 2064321 (1007 MB), flag 0x80
>         beg: cylinder    0, head   1, sector  1
>         end: cylinder 1023, head  31, sector 63


but,

# fdisk /dev/rsd0d
******* Working on device /dev/rsd0d *******
Warning: BIOS sector numbering starts with sector 1
parameters extracted from in-core disklabel are:
cylinders=4320 heads=64 sectors/track=32 (2048 sectors/cylinder)

Figures below won't work with BIOS for partitions not in cylinder 1
parameters to be used for BIOS calculations are:
cylinders=4320 heads=64 sectors/track=32 (2048 sectors/cylinder)

ie., I put the bios' figures in the disklabel, and can boot. So the
question now becomes, why can't one boot a scsi disk whose disklabel
doesn't match the bios'?

Just another thought: why have the 63 offset at the beginning of the
NetBSD partition as nothing else seems to be living on the disk?
(The zeroth block is the same in whatever geometry, isn't it?)

Patrick