Linsys NSLU2, one cool little NAS

Weighing in at a couple of hundred dollars the Linksys NSLU2 is a very tidy little NAS device. It's a small (three CD cases stacked) unit that holds a 266mhz PPC processor (underclocked to 133mhz), 40meg of RAM, two USB ports and one network interface. Linksys have fashioned together a Linux-based OS running Samba to provide a very tidy, home/home-office level NAS device that can be easily administered via a clean web-based interface.

The Linksys NAS connected to a 2.5" 80gig drive (click to enlarge)

Where the little box gets really interesting is its ability to be hacked in almost any direction. There is a large community of Linux hackers producing custom Flash images that allow everything from the addition of extra software packages to the installation of a full-blown Debian system on the tiny box. The hackers have cleverly got around the flash memory limits of the onboard hardware through a method known as 'unslinging', or more precisely the ability to boot and run the device off a connected hard drive. Coupled with this there is a raft of hardware hacks that range from the relatively simple (removing the underclocking on the CPU) through to the really difficult (boosting RAM to 256meg by soldering together RAM chips).

As soon as I read about the device I new I had to try one out to see if it was powerful enough to satisfy some PhD testing needs I have. On Tuesday the device turned up and after verifying the hardware was working I proceeded to void the warranty by installing the Unslung flash image and removing the hardware underclocking resistor. The Unslung image is a variation on the default Linksys OS, the major difference from the default OS being that it is 'unslung' to the external drive and the ability to install new software packages is provided. The available package list is surprisingly complete and very up to date. It includes such things as PHP 5.1, Apache 2, MySQL 4.1, CUPS 1.1 and Samba 3.0.22. The package management tool is called ipkg and I've found it very easy to use and surprisingly quick. New software gets installed into the /opt/ directory which makes experimenting and distinguishing between the default packages a lot easier.

With all these software packages its easy to put together a really powerful little NAS device that does everything from database driven PHP webpages to complex Active Directory integrated file and print serving. The only limiting factor is the 266mhz CPU and 40meg of RAM (which rules out really tricky stuff involving Java, Mono or Ruby). But ignoring this the device has a tonne of potential for the Linux software or hardware hacker. As it is only a few hundred dollars voiding the warranty is not really an issue, plus if everything turns to custard it is really easy to just re-flash the device with a pre-rolled image and start from square one again. The Linksys NAS is well worth the money if you are a tinkerer, in the market for a low-end file/print/web server or have a particular hardware/software project in mind.