Lime Technology unRAID

We've just finished our tests on a new NAS, the unRAID from Lime Technology.  But just so we're clear, it isn't actually NAS at all, but a piece of software that allows you to transform any ordinary PC into a secure NAS server.  Not only do we like the idea, but the price is pretty good too: the basic version is free!

We'd given up on testing anything from Drobo FS whose Beyond Raid concept had impressed us, so we went looking for an equivalent solution from other manufacturers.  After looking online, we found this unRAID software, developed by Lime Technology, which seems to do more or less the same things as Beyond Raid.  We read the info, picked through the wiki and the forum and said: why not test it?

What is unRAID?

unRAID is a piece of software that transforms just about any PC into a NAS server.  The basic minimum requirements are a 1 GHz processor and 512 MB of RAM, but there's a list of compatible hardware on the wiki.   The most important element is that your computer's motherboard can boot from a USB key.

That's because you install unRAID on a USB key.  The minimum recommended size is 128 MB, but if you want extra features you can you a 512 MB or 1 GB key.  The next step is to format the key using FAT32, make it bootable using a tool from Lime Technology, and then install the archive found on the Lime Technology site—and then you're done!  Once you put the key into your PC and start it up, you've got a NAS server.  All of the configuration is done directly on the computer, or from any other computer using a web-based interface, so you don't even need to know anything about Linux, which is what's at the heart of unRAID.

The Advantages: Security and Scalability
 

Let's take a look at why using unRAID might be a good idea:

We simulated the failure of one data drive by disconnecting it, and then we tried the same thing with the parity drive.  In both cases, our data was restored perfectly.

Everything isn't perfect though, and the unRAID still has a few small problems.  And that's probably a good thing, because otherwise, this free program (or affordable if you go for the Plus or Pro versions) would have almost certainly seen off hardware rivals from the likes of Thecus, Synology and Wnap.

To start with, the web-based interface is pretty minimalist and not always very clear.  In particular, managing the different users and their rights isn't that intuitive.  We sometimes struggled to work out what we had let everybody do and which folders they had access to, especially when we added several users.  Another problem is that you can't give access to a sub-folder inside a provide parent folder by giving it different rights.  That means, for instance, I can't give everybody access to a public 'Photos' folder inside my own private 'Vincent' folder.

The lack of a recycle bin for storing files before you're sure you want to delete them is a pain if you're not very organised.

In fact, looking at this as a simple NAS device, the lack of a recycle bin and the tricky configuration are both real negatives.

Next comes the fact that a whole series of options that come as standard on hardware NAS systems just aren't available on the unRAID.  However, because it's based on Linux, you can always add extras yourself as long as you know a little bit about it.  If not, some of the most common extensions are still accessible thanks to the detailed instructions found on the wiki.  Your author didn't have too much trouble installing the unTorrent BitTorrent client using the guide posted online, but for web servers and FTP, you'll have to roll your sleeves up and get your hands dirty.

Excellent Performance

To test the unRAID's performance, we used it with three drives, one of which was used for parity.  We mounted our shared folder on a Windows 7 network and ran the CrystaldiscMark test.  Here are the results we obtained, compared to the Qnap TS-219P, one of the best currently-available NAS, with two drives configured as a RAID-1 array.
 

The figures speak for themselves and the unRAID's excellent performance is immediately obvious.  These results were almost identical in both of the configurations we tried it with, an old AMD Athlon 3500+ with a Gigabyte K8N-SLI motherboard and 1 GB of RAM and an Intel Core i3 540 with an Intel DH55TC motherboard and 2 GB of RAM.  A Core i3 530 would have been perfectly capable of doing the job, but we didn't have one to hand.  The benefit of using Core i3 CPUs is that they don't use much power on standby, where they give Atom-based systems a run for their money before offering much better performance when they spring to life.

You can obtain even faster results if you use a cache drive.  That's an extra disk not connected to the backup system, which avoids the need for calculating parity data while writing and improves speeds.  The synchronisation with the other drives in the array is done afterwards, and you can choose how often this occurs, meaning you can benefit from increased speed without compromising on security.

You can also improve raw performance by deactivating shared folders.  Doing so means that every drive in the array is visible independently on the network but is still secure.  Read speeds can reach 70 MB/s and write speeds 40 MB/s, which means you're not far off reaching the physical limits of a Gigabit connection while writing data.

Manufacturing and Running Costs

As you can see, unRAID is a great way to recycle old hardware by turning it into a powerful NAS server.  But remember that one of the advantages of NAS is that it runs 24/7, so you'll also have to consider its electricity consumption.  With our first test configuration (using an Athlon 64 3500+), we measured 97 W while the drives were idle, but the change to our second option (an Intel Core i3 540) brought that down to 37 W, which would save you £70 a year on your electricity bill.  So, it will only take you a year to pay off that new motherboard, without taking into account how much you get for selling your old one second-hand.

If you want to start from the ground up, you can combine a motherboard, a CPU, some RAM, a cooling system and a case for around less than the cost of the Qnap TS-219P.  Factoring in the cost of the Pro version of unRAID gives a total cost more or less equivalent to a hardware NAS—for a solution that's faster and more scalable, but a little trickier to manage.

You can save even more by combing an Atom motherboard, CPU and cooling for well under £100.