[Samba] backup roaming profiles server

[Isaac]

How do I use a backup server to mirror my Roaming Profiles? I currently 
have a Samba server running as PDC, and it stores the profiles. I would 
like to have another computer available as a BDC, which can mirror the 
profiles in case the PDC dies or is somehow disconnected from the network.

There is a real possibility that my network might get chopped in half, 
and I'd like both halves to be able to keep running, until I can get on 
location to fix whatever is wrong.

My server is also a firewall/gateway and dhcp server. I'm going to set 
up the secondary/other server also as a gateway, so if my network gets 
segmented, a client pc can just be rebooted, and it'll get a new dhcp 
address with gateway that is connected to its part of the network. But 
if the BDC is on its part of the network, and the profile server is not 
available, it won't be good.

my PCs are win2Kpro and NT4 machines.

If anyone has a good solution, I would love to hear them!