Minimum Spec Required
What would you think the minimum spec for this would be?
A host server running AD/DNS/DHCP and Hyper-V with 4 virtual machines running off of it?
The 4 VM's are all file servers with another job (SIMS/Printing/WSUS/Sophos Ent Manager/SCCM) attached. Each VM will have it's own dedicated network card
I assume I will need a 2x Quad core box, but how much RAM? - Given the fact that this box will not go live until after 2008R2 SP1 and the Dynamic Memory feature that it brings to the table!
Minimum RAM would be 10GB, so each server had 2GB a piece, but I would not settle for less than 20GB (or 32GB) if I could get it. It would give each machine 4GB RAM (at 20GB) or 6.5GB RAM (at 32GB).
All of my servers had an absolute minimum of 4GB RAM dedicated.
Before the Dynamic Memory part I was thinking 24Gb, 8Gb for the host machine, 4 Gb for each virtual, but now I am wondering if I can do 2Gb for each virtual as a minimum, and allow the dynamic memory to allocate an additional 4Gb as it pleases (or rather have a pool of 12Gb for the 4 VM's to use).
I would highly recommend against relying on pooled memory for this sort of thing. For one Windows caches up avalible memory to improve speed and if you are overcommiting it then this overcomit feature will just cause an overall slowdown. Much better to give each of the machines their own dedicated memory space of an acceptable amount with only an extreme overhead allowance in a pool if you are going that way.
I would also suggest above 2GB per server probably 4GB for anything with a database ie WSUS, AV managment etc. Unless you are running stuff on your host OS though you should not need 8GB left free for it, I would be looking at 3-4GB of space for the host and leave the rest for the VMs, if you are usign Hyper-V R2 server core then even 2GB should be perfectly acceptable.
Under Hyper-V I use a min of 2GB for Windows 2003 servers, 4GB for 2008 / 2008R2 servers.
If you have a large number of SIMS users I'd got with 8GB or more.
We only reserve 2GB for the host.