virtualbox.org

Hello,
I'm new here, have read the FAQ, I hope I didn't miss the answer to this!

I'm going to be running a Windows SBS 2011 guest (64 bit) in virtualbox to future-proof a few clients on some modern server hardware - dual current generation Xeon's, 2 x gigabit LAN port Intel servers with 16GB of RAM and disk configuation yet to be determined, but probably a couple of 2TB drives (SATA) as a mirror of some flavour (NOT RAID5 or RAIDZ/RAIDZ2), maybe in hardware, but probably a software mirror. Running a windows SBS server in a VM is very compelling from a disaster recovery point of view - create a snapshot, no worries .. restore onto just about any hardware. Win ...

Anyway, I'm looking for recommendations for the host OS. I'm experienced with running RHEL/CentOS, Solaris (opensolaris and openindiana) and windows servers, so admin skills for choosing the OS for the host isn't a factor. I'm more interested in what host OS will be the most stable and efficient to run a SBS 2011 guest and the most future-proof (engage crystal ball now ...)? ZFS on open(solaris/indiana) is awesome, but I'm not sure if it's going to be of much benefit to a windows server?

I'd much appreciate any war stories or suggestions.

no-one? No opinions? An FAQ I missed?

Pick the one you're most familiar with and feel the most comfortable with as being stable. There is no "best" OS to run VB on, it's a user preference.