adding a second hard drive

[Dave Webster]

To solve a problem I'm having with /var running out of space, I decided
to add a second hard drive.

I found info at freebsd.org on adding disks using sysinstall and
followed the advice.  The old disk is a Maxtor 6Y080L0 80G as ad0 and
the new disk is a Maxtor 6Y120P0 as ad3.  I ran sysinstall, chose ad3
and parition it with: / 512M, /swap 2G, /tmp 3G, /var 4G, /usr
30G, /data 76G.  Did an installation with Kern source and documentation.
Added a new user, and set a password for root.  I added the FreeBSD boot
manager.

I rebooted to ad0 (didn't have the FreeBSD boot manager on this drive
yet), and found I could no longer login as the regular user and that my
root password was the one I had just set up on ad3.  I adduser my old
login and assigned it the original ID and got back the settings in my
home directory, although I don't know what I've doen to the
configuration files in /etc.

I tried to put the FreeBSD boot manager on ad0 with:
boot0cfg -B ad0 but get an erro:
boot0cfg: open /de/ad0: no such file or directory

I've googled this problem but have found little help except that it
shouldn't happen and it should be reported.

I'm running FreeBSD 5.4 stable.  I'm temped to start over from scratch
but would hate to lose everythin on ad0 without first transferring it to
ad3.  I've tried to mount ad3 and ad3c (the only references to ad3
in /dev) using:
mount /dev/ad3 /mnt/bigdrive but get an error:
mount: /dev/ad3 on /mnt/bigdrive: incorrect super block

So I'm pretty lost.  Any help would be greatly appreciated.  I've spent
4-5 hrs googling for solutions but nothing seems to work.

thanks in advance
Dave