I've been using a modified and streamlined version of Windows XP (which sometimes runs VMs) on my file server box, but I've already got SBS 2011 waiting to go onto it when I convert it to a proper client serving box. I'm also toying with the idea of converting another of my servers to a VMware ESXi box for things like my email server, firewall and a small web server.
ubuntu.. use putty to generate the private key so I can access the server anywhere- your netbook is a lot less suspicious that way if your ever searched at the airport, ect.. winscp with the same key to transfer files mainly use the server as a file repository and for pyrit (~95k/sec with a ati 6970).. write my own scripts ect for different types of attacks just for fun really- amazing to see what people use their rigs for.. and it's always fun to find the linux guru in the area at my sisters right now in michigan for my dads funeral.. the neighbor noticed had open wifi- found she was running linux (buffalo).. she came by to visit and I forgot had set up the yagi was pointed strait at her house XD she's all what's that? my sister told me she used to work for the cia I said.. it can be and changed the subject- but she knows what's up! so I might be getting buttsecked in prison.. I might like it too
Debian 6 x64 as host and HTPC + Debian 6 x64 guest for server + openwrt 10.03 guest for router + Server 2008 R2 guest for things that don't work on linux. Solaris for fileserver.
I'm running a copy of Windows 7 Ultimate on what I call my server. I've got a copy of WHS 2008 R2 through my MSDNAA account, but decided against using it. This was mainly because I wanted to use the server as a media centre connected to my tv aswell, and for that I like to use Windows media centre with the media browser plugin, which WHS can't do. It's also used as a rendering server using Autodesk backburner, and as a torrent downloader. Ultimately, I decided that that using a standard copy of windows was the easiest way to do all this, especially because I've had no experience of WHS and very little experience of Linux. I find it runs smoothly, without hitch with a Core2Duo E6600, 4GB ram, and a HD4870. Storage wise, it's got 4x1.5TB drives in raid5 for media, a further 1TB drive for downloads before they get organised, and an old 80GB system drive. All housed in an Antec300 full of gentle typhoons, under the stairs.
Windows Home Server, Windows Server 2008 or Windows Server 2008 R2 ? There is no such thing as WHS 2008 R2. If you meant Windows Server 2008 R2, then i don't know what are you talking about because i am using XBMC on Windows Server 2008 R2 Foundation without any issues. All i had to do was to install DirectX (and maybe some other dependencies). If you meant Windows Home Server, released in 2007, then that is a different story of course.
Oops, meant windows server 2008 R2. I might have been able to use XBMC, but I'm quite partial to media centre with media browser plugin. I've purchased most of the addition themes, and it looks stunning imo, and works great too. Sorry for the confusion. Got a little mixed up there.
windows server 2k3 on my fileserver. Never needed anything eles, never saw the point in overcomplicating. Plus the software for my RAID card works best in win32 systems.
Don't laugh.... but Vista Ultimate 64bit. It was the only OS I had a key for when I built the server. Thing is though... as time goes on, I see less and less reason to change it. It's been flawless. It's up 24/7 apart from rebooting after updates. Never lets me down. It's only a home file server, so I find no need to change it. I actually have a fully legal copy of WHS2008 r2... but it's so stable and works so well I can't be arsed changing it... I may do when I have more time... just to stop people laughing
Openmediavault, with a DLNA plugin for streaming. Fast, free and more than capable for my needs whilst being dead simple to install and configure.
Running unRAID with 10 disks at the moment. Using minidlna for uPnP streaming, airvideo to stream to iphone/ipad and SSH for remote access. Am looking to run Virtualbox on it for some VM's but just haven't gotten around to it.
If you need to get the best performance out of your hardware (in VMs) then VirtualBox might not be the best solution. It can have up to 30% overhead; have a look at container-based virtualization like OpenVZ. Never used it personally but seems to be the way to go for performance VMs (only 1-2% overhead)