What are the minimum RAM requirements for Server Core 2008 R2?
Solution 1:
Server 2008 R2 Core takes about 350 MB just to start. If you have a smaller AD and DNS install you can easily fit it in 512MB (without swapping going crazy). Anything smaller and you'll pretty much be swapping non-stop.
Solution 2:
I was running them on 256mb for DNS only - worked for some time ,but sometimes DNS would stop responding. Up to 512mb now, and it works like a charm. Hosts half a dozen zones only.