Hey people!
Since I struggled a bit getting my setup to a running condition, I though I'd share what I did in case other people face the same issues. Most of these parts are leftovers from builds I did for a company. I had some pretty good deals price-wise because of that but it limited my choice somewhat. If you have solid advice as to why not use certain parts it is appreciated! The goal is a solid box that'll last a long time.
Hardware
Case: Fractal Design 304
The case comes with enough stock fans to clear out the heat your disks, psu and cpu generate. Two fans in front (with dustfilter) and one big one at the back. The psu sucks air from the bottom of the case (with dustfilter) and pushes its heat out the right side. I like the build quality, it feels solid. Cable management is a b*tch though but not impossible. It can hold 6 3.5" drives or 6 2.5" drives or any combination. There is a switch at the back to control all fans (they're not connected to the motherboard in that case) with three settings.
PSU: Corsair CX430
Decent PSU from what I gathered online and with some headroom in case upgrades are desired later on.
Motherboard: AsRock B85M-ITX (Qualcomm Atheros AR8171 LAN chipset)
Somewhat a mistake, I should have gone for a board with more SATA headers. This one has only 4 SATA III connectors so with my setup it won't allow for additional disks in the future unless I go for a decent PCIE addon card. The LAN chip on this board is not supported out of the box, you'll need the backports kernel. In my case that meant installing OMV using another PC, more on that below.
CPU: i5-4460 (Cooler Master Hyper212 tower cooler, cpu bracket needs modding to fit motherboard because of some badly placed IC's (boo AsRock) and it's a tight fit in the case!)
Mainly chosen because I want enough capacity for streaming with Plex. The guideline is a 2000 Passmark score to decode 1080p/10Mbps content, so this cpu (6720 passmark) will be able to do a stream and then some.
Memory: 8 Gb DDR3
Storage: 4 x 3TB WD red
In Raid0 striped this is my main storage. No redundancy, I know, but my old NAS boxes are backup servers. I'm thinking something like OMVnas -> (all files) -> NAS1 -> (critical files only) -> NAS2
I haven't decided if I'd go for real time syncing or a nightly backup. I figure the nightly backup gives you a temporary protection against wrongfully deleted files. Any advice appreciated!
OS: OMV on 1 x 320Gb 2.5" WD on internal USB header on PCIe SATA controller
The original plan was to install on a USB stick, but since this is advised against (too many read/writes will wreck the device) I looked for an alternative solution. I chose to use the free USB2.0 header on the motherboard to connect a 2.5" 320Gb drive and mount it in the case. That proved problematic because the drive would get different UID's after longer idle periods. I installed an Asus u3s6 PCIe SATA controller to give me some extra sata ports. Worked out of the box. The disk is way too big but I couldn't find anything smaller (first world problems).
OMV can't recognise the LAN chipset, so I installed OMV on my target disk using an old laptop where OMV did detect the network adapter. I hooked up my disk to one of the USB ports and installing went smooth (just make sure you install it on the right disk, ideally disconnect other drives). Once OMV is installed you can enable the omv-extras plugin in the web gui. Then you can install the backports kernel which adds support for the AR8171 on my motherboard. I then installed it in my NAS and ran omv-firstaid as root. You'll have a menu option to detect ethernet adapters and voila, a running OMV.
I wish to thank the dev team as this is a great piece of software. I've been experimenting with available NAS solutions for a while now but OMV immediately felt like a match!
If you have any comments, tips/tricks or questions about my build: don't hesitate!
Happy holidays!
J.