Replacing both disks in RAID1

[Toomas Aas]

Hello!

I have a small server running FreeBSD 4.10, 2 x 80 GB drives mirrored on 
Promise TX2 integrated RAID1 controller. I'd like to replace the 80 GB 
drives with 200 GB drives.

Here's my current plan:

1. Attach one of the new drives to free ICH4 IDE port on motherboard, 
partition it and transfer the data using dump/tar.

2. Remove the 80 GB drives, attach 200 GB drives (one with data, one 
blank) to TX2 IDE ports and re-create the mirror using Promise onboard 
BIOS utility.

3. Reboot, fix the fstab (if necessary) and be done with it.

I have one doubt with it. Currently my partitions are ar0s1a (/), ar0s1b 
(swap), ar0s1e (/var) etc. When I create corresponding partitions on the 
new drive while it is attached to ICH4 controller, the partitions are 
created as ad0s1a, ad0s1b etc. When I then move this drive to TX2 port 
and re-create the mirror the partitions should again be ar0s1a, ar0s1b 
etc. Will it "just work" or will it not work at all?

Thanks in advance,
--
Toomas