This is a VMware ESXi 5.1 hypervisor running on an ASrock H77 Pro4/MVB motherboard with an Intel i5-3470 3.2GHz CPU and 16GB DDR3. This mobo/CPU combination allows VT-d, which permits me to pass the IBM M1015 SAS controller straight through to the NAS4Free virtual machine for speedy disk IO to the six SATA drives.
NAS4Free is configured with three sets of mirrored drives providing 3.62TB of redundant storage (~7.5TB physical). It provides this via NFS mounts to my OpenELEC HTPC, CIFS/SMB the the Windows machines, and AFP to the Macs. It also serves as a Time Machine backup destination.
Also running on the hypervisor is a VM dedicated to running Crashplan for off-site cloud backup. Mirrored drives are great for safe storage, until your house burns down. Or you accidently "rm -rf" in the wrong place.
The theme of this system is best bang for the buck. None of the components are particularly expensive but I've got plenty of headroom. If I want to mess with a transcoding/streaming solution like Plex, I just spin up another VM.
Booted into ESXi with no VMs running pulls 114W. Starting two VMs adds a negligible draw of 4W at idle. Under heavy IO load it pulls total 138W.
A couple things to note:
The motherboard H77 SATA controller cannot be passed through with DirectIO under ESXi 5.1. It causes a ESXi kernel panic when you boot the guest OS. It works fine under 5.0.
Also the Realtek integrated gig-E does not support jumbo frames under ESXi.
The IBM M1015 is a fantastic entry-level SAS controller. It's a rebranded LSI controller that comes with a lot of servers and gets tossed when admins boot from SAN or iSCSI. They wind up on eBay all the time. They can be flashed to support various configurations. However, I was unable to flash the controller on the ASrock mobo and has to use a different system to get the firmware I wanted on there. I'm not sure why but suspect it has something to do with UEFI vs. BIOS.
Lastly, FreeBSD systems (e.g. NAS4Free, FreeNAS, etc.) will hang on boot with the M1015 SAS controller in DirectIO mode. To fix this boot without the controller attached to the guest and add the following to loader.conf: