Yes, this is yet another self-made NAS post.. But when I was searching for information I had the feeling it was either with OpenSolaris/Solaris Express and ZFS or with Linux and some LVM. Some even dare to use btrfs which in my opinion is still in heavy development and not near stable. I’m not such a big fan of Solaris Express or btrfs for home use. I do like Linux or FreeBSD and ZFS. So it was clear for me, it would be FreeBSD with ZFS because of the native support for this FS.
Before I had this NAS I had 2 USB disk with ZFS in mirror attached to an OpenSolaris laptop but believe me, this is not an ideal setup, it worked but after one year of non stop operation scrubs constantly found data inconsistencies. Even after opening the USB cases and attaching the drives directly with a SATA cable ZFS was reporting errors. So, buy some new drives! (they’re really not so expensive)
So I ordered the following things.
1x SuperMicro X7SPA-H Atom D510 Mainboard, Retail
1x Lian Li PC-Q08 Black, No power supply
2x Kingston KTH-ZD8000B/2G 2 GB, PC5300, 667 MHz
1x Seasonic M12II-520 Modular, Bronze 520 Watt, 20+24 Pins
1x Lite-On LiteOn IHAS324 Serial ATA, Retail, Black
2x Western Digital Caviar 1,5TB WD15EARS-22Z5B1

Since it’s a home NAS I didn’t needed Enterprise grade performance but a low powered multifunctional device where I had the freedom to install what I want on it (that rules out Qnap, Synology..)
Some downsides of my configuration:
no graphic support in FreeBSD because of lacking GEM support (seems they’re working on it.)
no ECC memory, ECC memory is not supported on current ATOM boards. (this is also not offered by qnap or other home NAS builders)