Do I really need an excuse? \ud83d\ude42 <\/p>\n
Now I have a full, albeit small, Linux server at home, I’m sure I can think of some fun things to do with it. But as I wrote last week<\/a>, the catalyst that pushed me to doing this now was wanting something to collect data from my new CurrentCost electricity meter. <\/p>\n It needed to be cheap, small, and low-powered – no point having a server running all the time to monitor my home’s electricity usage if it makes a significant dent in my electricity usage all by itself!<\/p>\n What did I buy?<\/strong><\/p>\n A NSLU-2 – a network storage link for USB 2.0 disk drives, by Linksys. This is a small NAS device<\/a> that lets you make a USB harddrive available on a network. The firmware in it comes with enough software to create a network share for any portable USB harddrives or USB flash memory key that you plug in. <\/p>\n It’s a neat little gadget, but what makes it special is that it is very easy to flash the firmware and replace it with a full Linux distro. Plug in your USB harddrive, and you have a Linux server with as much space as you might want. <\/p>\n Oh – and for some reason, people call them “slugs”. <\/p>\n What did it cost?<\/strong><\/p>\n For the hard-drive, I spent £11.57<\/a> (again, including VAT and delivery) on a cheap-and-cheerful 4GB USB microdrive from ebuyer.com. <\/p>\n In total, my new home server cost me £54.46<\/b>. <\/p>\n Turning it into a Linux server<\/strong><\/p>\n There is a fantastic community site around the NSLU-2 at nslu2-linux.org<\/a> which contained all the info that I needed to get going. In fact, the whole thing took no time at all.<\/p>\n Here’s a quick overview of the steps involved.<\/p>\n The box comes with a CD with a setup wizard and manuals – didn’t need any of that. The device comes with a web admin interface – didn’t need that either. \ud83d\ude42<\/p>\n First step – choosing a Linux distribution. The NSLU2 site contains a ton of information on the different options available, but you can find a table with a good summary here<\/a>. I decided to go with SlugOS\/LE<\/a> – it’s small – based on OpenEmbedded<\/a> so there are a ton of packages already available for it, all optimised for embedded devices. Plus it comes with a recent kernel and recent version of glibc. It’s a Debian-like install – so installing new software is all straightforward – you can just use Once chosen, I downloaded the firmware binary image for SlugOS\/LE on the NSLU-2 from slug-firmware.net<\/a>.<\/p>\n Next you need something that will flash the firmware with the image – I downloaded the Sercomm Update Utility<\/a> from one of the mirrors<\/a> listed on the NSLU2 site, and installed it on my Windows laptop. <\/p>\n Before you can flash the NSLU-2, you need to put it in “Upgrade Mode”. This takes some fiddly mucking about with the reset button, but it’s well documented<\/a>. Once in Upgrade mode, you run the Upgrade Utility. You point it at the Windows machine’s network card, and it finds the NSLU-2 itself. It showed the current version of the firmware – which was the same as the version that the Linksys web admin specified – so that was enough reassurance to get me to specify the firmware image I’d downloaded and click “Upgrade”. <\/p>\n A few minutes later, the NSLU-2 boots up. By default, it has an IP address of 192.168.1.77 – you can SSH to it using the default root password<\/a>. <\/p>\n There is a utility called You use I used fdisk to divide my 4GB drive into three partitions:<\/p>\n Most of the space went to partition 1 for my root filesystem, partition 2 for swap space, with the remainder for my home filesystem. <\/p>\n There are clear instructions online<\/a>, but basically you create the filesystem, move the root filesystem from the NSLU-2’s flash memory to the USB harddrive, then set up the mounts. <\/p>\n And that’s it – a mini Linux server that’s ready to go. <\/p>\n Look at the pic of it next to a pen of mine – it’s not even as tall as my pen! <\/p>\n So far, I’ve only installed perl and python on top of the default distro, and I’ve still got a decent amount of space left:<\/p>\n I’ve not done anything interesting with it yet – I need to buy a cable to connect it to the CurrentCost<\/a> meter before I can start collecting data. <\/p>\n![\"the](\"http:\/\/farm3.static.flickr.com\/2399\/2508222553_9efeafb09f_m.jpg\")
<\/a>A Google Shopping<\/a> search turned up pyramid.com<\/a>. I bought the NSLU-2 from pyramid.com for £42.89<\/a>, which included VAT and next-day delivery. I’d never heard of them before, but as first impressions go, their service seems pretty good.<\/p>\n![\"unpacking](\"http:\/\/farm4.static.flickr.com\/3278\/2509050200_c2335d28fe_m.jpg\")
<\/a>Unpack the NSLU-2 and plug in power and an ethernet connection. <\/p>\nipkg<\/code>. <\/p>\nturnup<\/code> to do the basic startup configuration. This is well-documented<\/a>, but even without that, there is a default motd<\/a> message displayed on login that walks you through the steps. <\/p>\nturnup init<\/code> to set the basic network config parameters. Then you plug in your harddrive, and set up the partitions for your Linux installation. <\/p>\nDisk \/dev\/sda: 4095 MB, 4095737856 bytes\r\n128 heads, 63 sectors\/track, 992 cylinders\r\nUnits = cylinders of 8064 * 512 = 4128768 bytes\r\n\r\n Device Boot Start End Blocks Id System\r\n\/dev\/sda1 1 600 2419168+ 83 Linux\r\n\/dev\/sda2 601 787 753984 82 Linux swap\r\n\/dev\/sda3 788 992 826560 83 Linux<\/pre>\n
![\"wow,](\"http:\/\/farm3.static.flickr.com\/2377\/2508222195_da2572edae_m.jpg\")
<\/a>In fact, I’m still amazed at just how tiny it is. <\/p>\nroot@minipooter:\/$ df -h\r\nFilesystem Size Used Available Use% Mounted on\r\n\/dev\/sda1 2.3G 80.5M 2.1G 4% \/\r\n\/dev\/mtdblock4 6.4M 4.8M 1.6M 75% \/initrd\r\n\/dev\/sda1 2.3G 80.5M 2.1G 4% \/dev\/.static\/dev\r\ntmpfs 2.0M 28.0k 2.0M 1% \/dev\r\n\/dev\/sda3 794.5M 16.0M 738.1M 2% \/home\r\ntmpfs 14.8M 0 14.8M 0% \/var\/volatile\r\ntmpfs 14.8M 0 14.8M 0% \/dev\/shm<\/pre>\n
![\"setup](\"http:\/\/farm4.static.flickr.com\/3213\/2509049808_f9cb012d86_m.jpg\")
<\/a>But in the meantime, the server has already taken it’s place next to the CurrentCost meter. <\/p>\n