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DIY Thunderbolt DAS

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October 28, 2013 6:01:41 AM

Not sure if this is the most relevant category for this or not, it's a bit of a tricky one to categorise.

Okay, so what I want to do is to build a high capacity DAS machine, probably something in the region of eight or more 3.5" bays.

The main difficulty I'm having is that although I've built PCs in the past, I've never built a more specialised DAS box. While I can't imagine the actual construction is much different, I'm having a nightmare of a time finding parts.

In particular I can find plenty of 8-bay or better pre-made devices, but no case-only products; but I can't really use a pre-made device as most are SATA expanders requiring compatible eSATA or Mini-SAS, both of which usually require an add-on card, but I'd really prefer to just use Thunderbolt to connect it as this is what I see myself using in future, and should ensure Mac compatibility.

Secondly, I don't know much of anything about storage controllers. Other than a Thunderbolt port (or some way to add one) I don't have much in the way of requirements; although on-board RAID would be nice, I'm fine just having all the drives available via JBOD as turning them into a ZFS pool will probably suit me fine. I'm assuming JBOD over Thunderbolt shouldn't have any particular compatibility issues, but I'd like to ensure Mac compatibility in case that's what I use it for in future.

Anyway, I'm looking for advice and recommendations on how I would do this, to summarise here is what I have in mind:

- 8 or more 3.5" hard drive bays.
- Preferably a tower case that's as slim as possible, but with adequate, quiet cooling.
- Thunderbolt connection.
- RAID only at a reasonable price otherwise JBOD is fine.

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October 28, 2013 9:44:30 AM

Okay, so I've continued my own research and have made a bit of head-way.

I had a look at this guide, which seems like it has a good sized case, but I haven't been able to find anything quite the same so far. It's still probably larger than I want though, as I'm not too fussy about drives being hot-swappable so I don't particularly need it to have 5.25" bays, do cases of this type exist at all for 3.5" drives? I've seen pre-made units like Sharkoon one, which is only 15cm across so a lot more like what I want, but do cases like that just not exist on their own? Am I wasting my time looking?

I also found some products by DAT Optics which are interesting, for example this USB to 5x SATA RAID/JBOD SCSI Panel. Okay so I said Thunderbolt in my first post but I just can't find anything connecting SATA to Thunderbolt except some obscenely expensive external devices, and internal controllers only available to OEMs. Anyway, I figured I might be able to use two of those USB controllers, and hopefully DAT Optic will release a Thunderbolt equivalent eventually, as they've already started to create Thunderbolt panels, though only for single SATA connections so far.

It's a bit disappointing, but if I limit each USB port to four drives then 5gbps should be adequate for me as I'm only use HDDs for now anyway.
October 28, 2013 2:34:25 PM

Okay so I did manage to find out what the case in that article is; it's actually the case for a CD/DVD duplicator, not that that makes it unsuitable for a storage array, though it's been a bit of a pain to find many supplied as just the case and maybe power supply, and harder still to get them with decent cooling arrangements (most just stick tiny fans at the top, which may well be fine but I always prefer larger, quieter fans wherever possible).

Anyway, it got me to thinking; could I make my own case? Or more specifically, is there something I could mod to become a case, e.g - a metal storage container, maybe even a metal briefcase?

It sounds kind of silly, but then the thing is, a device like this really doesn't need much space, meanwhile regular PC cases and even the duplicator units would leave me with a ton of wasted space at the back.

What I was thinking is that I could try to build a case around two of these, stacked by their short sides to make a tower with 10 horizontal HDD bays. Then all I need is enough room for a Power Supply and the USB to 5x SATA RAID panels that I linked to earlier.

Anyone have any idea how much space I should allow for, and what the best power supply option would be for this? I'm wondering actually how feasible it would be to make a tower that's just deep enough to fit those back planes, and put the power supply and cards either at the top, bottom or middle of the case. That'd give me a rough tower size of 14cm wide by 45cm high by 20cm deep or so, that sound about right?
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February 14, 2014 7:27:53 PM

Hopefully you keep us posted , Sorry I can't be more help. I am interested in it too.

I have used a few different NAS 2bay and they always seem to be so slow. I have my pc on sleep because i can't stand waiting around. I have a few DVR or PVR to record the tv because I can't stand watching the adverts. I only got so much time on this earth. When my DVR/PVR filled up i transfered my files/movies to another cheap NAS i got from ebay and it filled up , 2T of stuff. I had 1T of stuff from the PVR. Now i am looking for something else.

February 15, 2014 4:24:43 AM

My project is actually underway, I'm hoping to post a build-log once I'm finished.
I'll give a quick summary of what I've learned so far:


  • Modifying cases is a pain in the ass. In the end I opted to get a cheap 9x 5.25" bay PC case (got mine from MS Tech), thinking I'd just chop off the back 10cm or so, flip the PSU vertically and I'd be good to go. However I badly underestimated how strong even half a millimetre of steel actually is. Fortunately I have the tools to do it (hacksaw, pillar drill and a jigsaw) but if that kind of task doesn't appeal then I strongly recommend just finding a PC case you can make do with as-is. Fortunately I'm nearly finished modifying the case, just need to finish the new hard-plastic back, which should leave me with a neatly proportioned case only 30cm deep (front to back).
  • ATX PSUs want motherboards! This probably sounds really obvious, but I hadn't even considered that an ATX PSU wouldn't work without a motherboard to provide the PS_On signal. Once I found this out there is a fairly simple fix (shove a paper-clip into the right pins on the motherboard connector).
  • Modern PSUs have sense wires! Following the above problem I opted to make up a replacement cable since I bought a fully modular PSU. However, if you go this route then remember that all modern PSUs have at least one sense wire that allows them to check that voltages are within safe operating limits; I forgot this and ended up with a PSU that switched itself off immediately after being switched on. Now that I've sorted this though I have a custom cable providing me access to all the motherboard power options, which I'm using for my RAID controller(s), instead of adding splitter cables to other connections.
  • Contrary to popular belief, not all PWM fans will run from a 3-pin fan connector. One of the plus points of the case I decided to modify is that it has a convenient space above the chassis where I could fit a case fin 2cm or less in thickness. I opted for a Prolimatech Ultra Sleek Vortex 14, a 140mm fan with 120mm mounts and only a 15mm thickness. It's actually a great fan, but only available with a PWM connector, and it won't run from a 3-pin fan connector except at full speed (which is no good). I do recommend the fan for any space restricted build though, just make sure you can provide a PWM signal to it; in the end I managed to get a great little 3-pin to 4-pin adapter with a variable resistor that allowed me to set the fan speed to less than 100%, so now I can run my case almost completely silent.
  • DIY Thunderbolt is a pain in the ass. When I started the project, DAT Optic produced a Thunderbolt to SATA III bridge board, that would have been ideal for transforming one of the USB3/eSATA RAID controllers I'm using into a Thunderbolt one (well, at 6gbps anyway). However I really should have ordered it on day one, as it's since been discontinued and I can't find anything similar anywhere else. DAT Optic say they're about to release a Thunderbolt 2 based RAID controller, but won't give any indication as to when, or whether it will be available as a consumer part, so I'm pretty much stuffed when it comes to Thunderbolt. Fortunately USB3 still meets my needs (so long as I only use a single RAID array per connection), and maybe in future someone will produce an eSATA to Thunderbolt adaptor cable. If someone does produce a Thunderbolt RAID controller, then since this is a DIY project I should be easily able to swap it in, I just don't know when that will be, if ever.
  • I really like the Prolimatech Ultra Sleek Vortex 14's. Okay, so the PWM issue is annoying, but otherwise these are actually really good fans; I haven't found any others in a similar size that are only 15mm thick, and the fans are actually really good in spite of this, at least as good in fact as any 25mm thick 120mm fan I've used. They're intended mainly for CPU coolers and I'm sure they're great for that, but they also make a good case fan, and in any space constrained build I'd strongly recommend them. Not that my build is that constrained, but by mounting the fan on the outside of the main chassis (but still inside the top of the case) I can keep more space clear for air to flow through. The fans aren't quite as quiet as claimed in the specs when running at full speed, but at 500rpm (about as slow as it can go) it's completely silent except for a slight noise from the motor up close, though you shouldn't hear it once it's in a case. They're a tad pricy, but 1cm is actually a lot of space to save in your case, and the more empty space you have the better your airflow seems to be; same reason why you should always route your cables as neatly as possible. In my case I have just this one fan for cooling up to 10 hard drives and my passively cooled PSU, and it does the trick nicely even at its lowest speed.


  • So yeah, pretty mixed result. The whole project looks like it should come in under £520 which isn't bad given the UK's 20% VAT rate, and it'll give me a total of two 5-disk RAID arrays, each using its own USB3 or eSATA connection. I'll be using one as a RAID-5 for my main needs since it gives a good balance of performance and redundancy, with the other providing a concatenated array for use as a backup; I'm hoping to switch that to a RAID-5 as well, but I'm just using disks I already have for now and they don't match in size. I also still have three 5.25" bays free, which means I have room for another five 3.5" drives, or up to twelve to eighteen 2.5" drives! In theory if I swapped out the backplanes I already have and went all 2.5" drives in future I could pack up to fifty-four 2.5" drives into this one box, so I'm hoping I won't ever have to change my storage enclosure except to upgrade or replace parts :D 

    I'm still pleased with how the end result is shaping up, and if you go into it knowing how to switch on the PSU, and don't try to modify a case, then I think it should be a lot less difficult than I've found it to be. But for now I don't think a DIY Thunderbolt array is possible at all, and I'm not sure if that will change in future, unless maybe I can get my hands on some of the controllers found within existing RAID array products somehow.
    March 18, 2014 5:11:50 PM

    Just for the speed shake - you can stripe your TWO 5x drives RAID5 as RAID50 - you will getting about 450MB/s

    Of course, you must use eSATA connection
    March 21, 2014 10:33:50 PM

    FireWire2 said:
    Just for the speed shake - you can stripe your TWO 5x drives RAID5 as RAID50 - you will getting about 450MB/s

    Of course, you must use eSATA connection


    I am thinking of using a i3-4130T (35W TDP), i have not picked the motherboard. Some of the folk i have talked with ,tell me to go for something with a C226 Chipset because then i can use it for virtualization and use a xeon cpu. I am thinking just a NAS is ok. I want to move tv/media stuff into it .Id be very interested if i had the ability to just jump over adverts rather then fast ford as the retail pre built systems do. I suppose if i can use a media player of some sort to play the stuff i record on tv, i can just point and click.

    thanks for keeping me updated on your progress.
    March 25, 2014 5:01:21 PM

    Duckhunt said:
    FireWire2 said:
    Just for the speed shake - you can stripe your TWO 5x drives RAID5 as RAID50 - you will getting about 450MB/s

    Of course, you must use eSATA connection


    I am thinking of using a i3-4130T (35W TDP), i have not picked the motherboard. Some of the folk i have talked with ,tell me to go for something with a C226 Chipset because then i can use it for virtualization and use a xeon cpu. I am thinking just a NAS is ok. I want to move tv/media stuff into it .Id be very interested if i had the ability to just jump over adverts rather then fast ford as the retail pre built systems do. I suppose if i can use a media player of some sort to play the stuff i record on tv, i can just point and click.

    thanks for keeping me updated on your progress.


    Once you have OpenFiler or FreeNAS installed and with those Hardware RAID above, you can use iSCSI to allocate a block and run the virtualization on it... It does not need all the XEON and C226 Chipset
    Note; this is a head-less NAS-iSCSI
    !