switching IDE controllers

[kirt]

i've checked the handbook, man pages, web, etc. for info regarding
this and i'm still not entirely sure as to how i should go about it.

FreeBSD daemon.pwnd.local 4.7-STABLE FreeBSD 4.7-STABLE #6:
 Sun Mar 30 08:50:48 EST 2003
root at daemon.pwnd.local:/usr/obj/usr/src/sys/DAEMONSMP  i386

dual AMD 1200 MP, 512 RAM

my original FreeBSD server was an older PC that did not have an
ATA100 IDE controller on-board, so i used a Promise TX2 ATA100
controller for all my drives, and just left the CD and DVD-roms on
the slower on-board controller.

now, later down the road, i've upgraded quite a bit and the server
has an on-board AMD 766 ATA100 Controller and i'd like to add some
drives to the setup.  i figured now would be as good a time as any
to move my main drive off the Promise card and on to the motherboard.

here are the 4 drives i currently have (from dmesg)

ad4: 19092MB <WDC WD200BB-75CLB0> [38792/16/63] at ata2-master UDMA100
ad5: 38166MB <WDC WD400BB-32CJA0> [77545/16/63] at ata2-slave UDMA100
ad6: 38166MB <WDC WD400BB-00CLB0> [77545/16/63] at ata3-master UDMA100
ad7: 38166MB <WDC WD400BB-75AUA1> [77545/16/63] at ata3-slave UDMA100

and the CD-ROM and DVD are on the on-board secondary IDE channel.

i want to take ad4, which is where FreeBSD is installed and all of my
main partitions are (/ , /var , /tmp , /usr , and the swap), and move
it to the on-board controller.  the other 3 drives are nothing but
data for samba shares.

i am not using the boot manager.

i've gathered that i will have to change the mount points in
/etc/fstab to reflect the new drive location (ad0), but past that i
am unsure as to what all needs to be done to have the machine boot
correctly.

i'm also a little afraid to just "experiment" because i have a lot of
really important stuff on here.  =)

thanks in advance.

--
-- kirt
-- www.pwnd.org