It's hard to disagree with either. You basically want to separate data. If you do not have different drives or RAIDs, then partion. So, we are all on the same page here, I like to say "partitions" when talking about separating "one drive" into multiple partitions, but it is still only one drive. When I have what James has, I like to call it three drives. It's semantics, but it tells the listener right away three different drives or RAIDs.
I believe you should always have two or more drives. My server has a RAID1 just for the OS and a RAID5 for data. Now, I partition my data drive but I still have the benefit of a separate drive.
When you have a separate drive for data, this allows you, if necessary, to only back that up, although I do back up the entire server. But, I would say data to system is like 25 to 1. If I had to choose between losing the system or the data, I will go with the data every time. You can always simply reinstall the OS and you're good to go. Sure, you have to do AD over again, and you would have wanted to have SharePoint and Exchange backed up -- my SharePoint and Exchange is on the data drive any way and is backed up nightly to an external drive. AC, as much as I hate it, is on the data drive. And Best Practices would dictate that you have your paging file on a separate drive. Even better on a separate partition on a separate drive.
Your question does beg the question why have a server with a top notch OS in a peer to peer. That's like having a Porsche 911 and driving 35 mph everywhere. Why not just use WIN 7? Any reason not using 2011 or 2012? Just asking.
Just so everyone knows, this isn't a Client/Server vs P2P debate, this is you already have the hardware/software, why not go with the domain.
And, yes, I would like to hear that story.
