removing geom config left over from previous install

[Gayn Winters]

> [mailto:owner-freebsd-questions at freebsd.org] On Behalf Of 
> Robert Fitzpatrick
> Sent: Friday, May 05, 2006 10:35 AM
> To: FreeBSD
> Subject: removing geom config left over from previous install
> 
> 
> Trying to mirror the system using geom on a box with 2 pairs of
> identical SCSI drives (2 IBM 9GB drives and 2 Seagate 35GB 
> drives). The
> Seagate drives were mirrored with geom under a previous install and I
> was trying to mirror the system, when all was not working and 
> I decided
> to start all over again. I have tried a few times now with a fresh
> install of FreeBSD 6.0 and on the last round, removed and 
> wrote changes
> to the disk in the splice setup for all four disks and then restarted
> the machine and installation to make sure I had all disks 
> with one slice
> of unused space to start. I did, so I proceeded to create all my
> partitions on the one IBM da0 drive to mirrored with da1 
> after install.
> The issue is that after loading the mirror, I get what seems to be my
> previous devices, how can I get a fresh start? Because this eventually
> leads to 'bsdlabel: Geom not found'...right after first boot, I am
> following the doc at http://people.freebsd.org/~rse/mirror/
> 
> files# dd if=/dev/zero of=/dev/da1 bs=512 count=79
> 79+0 records in
> 79+0 records out
> 40448 bytes transferred in 0.015124 secs (2674452 bytes/sec)
> files# fdisk -v -B -I /dev/da1
> ******* Working on device /dev/da1 *******
> fdisk: invalid fdisk partition table found
> parameters extracted from in-core disklabel are:
> cylinders=1115 heads=255 sectors/track=63 (16065 blks/cyl)
> 
> Figures below won't work with BIOS for partitions not in cyl 1
> parameters to be used for BIOS calculations are:
> cylinders=1115 heads=255 sectors/track=63 (16065 blks/cyl)
> 
> Information from DOS bootblock is:
> 1: sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
>     start 63, size 17912412 (8746 Meg), flag 80 (active)
>         beg: cyl 0/ head 1/ sector 1;
>         end: cyl 90/ head 254/ sector 63
> 2: <UNUSED>
> 3: <UNUSED>
> 4: <UNUSED>
> fdisk: Geom not found
> files# gmirror label -v -n -b round-robin gm0s1 /dev/da1s1
> Metadata value stored on /dev/da1s1.

The geom metadata is stored in the last block of the slice.  Zero it as
well and you can have a clean start.

-gayn

Bristol Systems Inc.
714/532-6776
www.bristolsystems.com