I have a small network (20 users). I'm looking at moving around what roles are on which servers. Layout is currently (servers 1-3 are pretty beefy):
server 1 - SQL server
server 2 - terminal server
server 3 - test server / DC (not currently a test server but was)
server 4 - DC / primary DNS
server 2 was also a DC but i changed that to server 3 after reading a terminal server should not be a DC. I know it is not ideal but is it ok to have server 1 also be a DC/secondary DNS server? Or is this just as bad as having the terminal server a DC? Currently I have no secondary DNS server and DHCP is being handled by our firewall.
Furthermore, if you have suggestions for re-arranging what server should host what services, I'd love to see that as well! From what I understand we need.
Primary DNS server
Secondary DNS server
We may add (roughly in order)
File server (external network hard drives have been fine thus far in our small network)
test server (no current need, but always nice)
We don't currently see a need for exchange or anything else.