Problem creating DR bootable disk

[Joe Gross]

I'm running FreeBSD 6.1-RC #0 with a generic kernel and an Asus A8V
motherboard. I have three IDE disks in my system. Two are on a 3ware
7200 RAID card in a RAID1 configuration. This is currently used to
boot.

The third disk is intended to be a DR disk, with a nightly script to
mount, sync, change twed0 to ad0 in fstab, and unmount. If something
untoward would happen to the main RAID, I could simply reset the boot
list in the BIOS and boot off the DR disk that has an image from early
that morning. This is also a handy way to "shuffle" the OS onto larger
disks as I upgrade.

I was using this in 4.10 with an Asus a7v133 board and fortunately
never had to utilize the DR capability. It did pass tests for booting
off the new disk and I did several disk upgrade shuffles over the
years.

For 4.10 the script I used to initialize the DR disk and add boot
blocks was:

#!/bin/sh
dd if=/dev/zero of=/dev/ad0 bs=1k count=1
fdisk -BI ad0
disklabel -B -w -r ad0s1 auto
disklabel -R -r ad0s1 disklabel.250
disklabel -B -r ad0s1
newfs -U -i 20480 /dev/ad0s1a

This doesn't work with 6.0. When I try to boot off the secondary disk
it gets through the initial loader and then spews what looks like a
repeating register dump. Nothing short of a power cycle will kill
it. I can't say exactly what it says since it's scrolling too fast to
read.

Everything I've read indicates the procedure hasn't changed in
6.0. Any suggestions on where to look or what to try?

Thanks for the help,

Joe