I'm looking at putting together a low power NAS that would run 24/7. I also want some redundancy so am looking to either include a controller that does RAID 10 (1+0 not 0+1) or use software RAID in linux. I intend to set up 6 drives of about 750GB to give me 2.25TB total (probably WD caviar green). This will also have a 1 in 5 chance of second drive failure causing data loss. The NAS would be for storage of data for home use i.e. videos, photos, docs etc that can be connected to while I'm at home.
In addition I then want a system that would be used as a home theatre PC. As this would be a more power hungry system, my first thought is to keep them separate.
I've been checking out the integrated Atom mini-ITX boards (N230 with passive cooling); however, in order to connect 6 drives, a third party controller would need at least a PCIe port, which is missing on a lot of these.
While I like the idea of the small form factor and ability to use a small case, I'm not sure if I'd actually be getting the lowest power setup, particularly as it would be at idle about 95% of the time.
Would a standard ATX/mATX board with integrated graphics be able to achieve similar power ratings? Are there any that can be passively cooled (without water cooling mods) to be silent? There are some boards that have 6 internal SATA ports, but that leaves none spare for a DVD drive or a boot drive, so the 3rd party controller would be required here as well.
In order to connect the drives I've been thinking of using a controller with a silicon image chip such as SiI3124 or SiI3132 that support FIS based switching for SATA port multipliers.
I have heard that the Atom CPUs don't actually have much range in their power draw i.e. close to 25W whether idling or maxed. Is this the case (not sure if it's power or TDP)? If so, then would a combined system such as an Athlon II X3 405e on a board with a 785G chipset actually draw less power at idle and then have the grunt to do the home theatre work? This would mean using Windows 7 as the host operating system and sharing the drives through windows rather than a dedicated file server. Windows would have to run a software RAID I think (does it work?). In this setup, I'd install the OS on a separate SSD. I think this drive would need to be on the main Mobo controller and not connected to a 3rd party controller. So really I'd be needing 8 SATA ports - SSD for OS, 6x drives in RAID, and blu-ray. I couldn't find any current generation integrated controllers that support SATA port multipliers (the next gen SB810 and SB850 may support them), thus the need for a PCIe SATA controller.
Well, there's lots of questions here that I hope someone can help with. I seem to be going around in circles at the moment.
Well, I've made some progress regarding the basic decisions i.e. type of board and chip etc.
Looking at even the lowest power CPUs available, when combined with the power usage of the motherboards and fancy graphics chipsets on the mATX and ATX boards, they seem to require about 3 times the power of an Atom on a mini-ITX board. As I'd like to be able to run the NAS 24/7 I've decided to try to find a suitable Atom and mini-ITX board and do a separate system for a HTPC later.
First off, a NAS doesn't require HD video output, so the latest ION chipset boards are out. I was checking out Intel's offerings and found that the 945GSE chipset produces about 6W TDP while the 945GC produces 22W (these are maximums). The 945GSE doesn't do quite so much in the graphics department and the 945GC but the main functions are similar. Memory bandwidth is about half... but not really critical here. The 945GSE chipset is paired with the Atom N270 for use in netbooks where thermal output is critical.
My other requirements have also been decided; these are:
- Gigabit LAN
- PCI Express slot - 1 lane is OK (2.5Gb/s so doesn't actually max out even one SATA connection - still it is more than adequate for storing data and even for playing back my DV files at 200MB/min)
- PCIe SATA controller card with 2 ports Silicon Image SiI3132 chipset. This will be connected via a flex PCIe riser. With two internal ports it can then have a SATA to eSATA connection to the rear of case.
- SATA port multiplier - 2 off to split each eSATA port. These would be in the drive enclosure, which will be hidden (sound insulated and fire insulated if I can manage - need some sort of fire damper for the vents)
- OS drive to be either Compact Flash or SSD for silence.
I found a SATA controller by Syba on Newegg, but they don't ship outside the US... May be able to source from Amazon. Very cheap. Not sure of quality.
A mini-ITX board that seemed to be suitable is from ibase called the MI810F. The "F" model has gigabit LAN. It has PCIe x1 port, and says it has a CF socket. I'm not sure where to actually buy it though.
Addonics have some port multipliers with a Silicon Image chipset.
The SATA controller chipset says that it supports RAID 0, 1, 10 etc but it doesn't actually do it itself, so software RAID will be required.
Can someone tell me how safe my data is if my OS drive fails? Does it keep some sort of catalog of the RAID that would be difficult to rebuild in the case of failure? Particularly if I didn't know exactly where each drive fit into the array.
Still to be determined:
- Drive enclosure
- Finding someone that has all the parts and that will ship to Australia.
- CF or SSD drive for the OS.
- OS to use. Generally use SuSE Linux. Think they may be one of the distros that support the Silicon Image chipsets. Haven't looked at FreeNAS as yet. May test it virtually first.
- Power supply for drive case and motherboard.