Re: bootable disk: how?

[der Mouse <mouse%Rodents.Montreal.QC.CA@localhost>]

>>> Okay, I give up.  What does it take to make a disk bootable?
>> Having recently felt your pain, I can offer a couple of suggestions.
>> fdisk -c /usr/mdec/mbr /dev/rwd0d
>> fdisk -a /dev/rwd0d
>> to insure the active partition is the correct one.
>> Be sure to check and make sure the disklabel and partition tables
>> agree on which sector the 'a' partition begins.
>> cd /usr/mdec
>> installboot -v -o <options, usually console> /dev/rwd0a bootxx_ffsv1
>> Finally, the one which has tripped me up most recently, is to check
>> and make sure you have a modern copy of /usr/mdec/boot in the /boot
>> file of the filesystem you're booting from.

I just did these.  fdisk -c.  fdisk -a.  cd /usr/mdec and installboot.
copy /boot (using "cat >", to ensure no holes).  Rerun installboot.
Still no joy.

However, there is one thing I noticed.  When running fdisk, there's a
line "fdisk: Cannot determine the number of heads".  It isn't much, but
it's the only thing I see that could be relevant.  fdisk says

Disk: /dev/rwd0d
NetBSD disklabel disk geometry:
cylinders: 8940, heads: 15, sectors/track: 63 (945 sectors/cylinder)
total sectors: 8448300

BIOS disk geometry:
cylinders: 525, heads: 255, sectors/track: 63 (16065 sectors/cylinder)
total sectors: 8448300

Looking at the fdisk source code, I can see where this message comes
from, but I don't know enough about i386 disk formats to tell anything
useful from that.  Could whatever is behind this prevent booting?

I'm tempted to dd /dev/zero over the first meg or two of the disk, then
use the 4.0 install CD.  If *that* doesn't give me a bootable disk, I
think giving up might be a reasonable option. :)  (If it *does* give me
a bootable disk, then I can copy all the data back onto it and try
again.)

/~\ The ASCII                           der Mouse
\ / Ribbon Campaign
 X  Against HTML               mouse%rodents.montreal.qc.ca@localhost
/ \ Email!           7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B