Can't add new 1TB disk in FreeBSD 6.1

[Don O'Neil]

> I just swapped out an old 500G disk with a 1TB one and I'm trying to 
> label it and mount it...
> 
> If I run bsdlabel -w ad4, I get:
> 
> bsdlabel: Geom not found
> 
> If I run sysinstall, it tells me that it can't write to the disk.
> 
> I've tried an old 'bypass': sysctl kern.geom.debugflags=16, but that 
> didn't help.
> 
> Can anyone help me get this new disk installed without having to boot 
> off a recovery CD? The server is 500 miles away from me and I don't 
> have direct console access.
> Can you provide output from dmesg, as well as "geom disk list"?

OK... I tried:

# dd if=/dev/zero of=/dev/ad4 bs=512 count=1000
dd: /dev/ad4: Operation not permitted

# fdisk /dev/ad4
******* Working on device /dev/ad4 *******
parameters extracted from in-core disklabel are:
cylinders=1938021 heads=16 sectors/track=63 (1008 blks/cyl)

Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=1938021 heads=16 sectors/track=63 (1008 blks/cyl)

fdisk: invalid fdisk partition table found
Media sector size is 512
Warning: BIOS sector numbering starts with sector 1
Information from DOS bootblock is:
The data for partition 1 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
    start 63, size 1953525105 (953869 Meg), flag 80 (active)
        beg: cyl 0/ head 1/ sector 1;
        end: cyl 612/ head 15/ sector 63
The data for partition 2 is:
<UNUSED>
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
<UNUSED>

Geometry output:

Geom name: ad4
Providers:
1. Name: ad4
   Mediasize: 1000204886016 (932G)
   Sectorsize: 512
   Mode: r0w0e0
   fwsectors: 63
   fwheads: 16

Nothing exciting coming from dmesg.