How to change a disk?

[Water NB <netbsd78%126.com@localhost>]

I know how to add a disk to an existing system,
but now I want to change a bigger disk.
(My box is NetBSD-4-AMD64)

I do:
1) add the bigger disk to my system.
2) power on, disklabel it, newfs it
3) mount it to /newdisk
4) copy all files
cp -rp /usr /newdisk
cp -rp /etc /newdisk
...
5) power off and get rid of the old disk

any more to do?