The Tenuous Link

Like all good gadgets, I know loads of things I can do with Knoppix, but I'm not really sure what it's actually for. It's free to get hold of though, so you have nothing to loose but your time if you try it out.

Knoppix is a Linux Live DVD (or a smaller version is available as a Live CD if you still use those). That means that you can put it in your computer when you switch it on, and instead of starting up in to the Windows desktop (or whatever) you normally load from the hard disk, your computer will run Linux and the KDE desktop from the CD. If for any reason Knoppix doesn't get on with your hardware (unusual), or when you are done, then just reboot your machine and you are back to how you were before.

At a superficial level, the Knoppix desktop looks a lot like a Windows desktop, except the background wallpaper image is different. You get a selection of icons to click on that will start various applications from web browsers, to word prosessors, to web servers. Most of the software you'd expect to have after you installed Linux on to your hard disk is available, except of course you haven't actually installed anything on your hard disk. So Knoppix is great for checking out the latest eye-candy in Gnome or KDE without having to install the monsters.

It's also great if you need to check what your web site looks like in a non-Windows browser. oliverbeale.com is unreadable in Firefox in Linux, for instance, but is just about OK using the Konqueror browser.

Also very useful if you are replacing a hard disk. I used a USB disk caddy and a Knoppix CD to clone and stretch my system partition and the rescue partition on to a new larger hard disk for my laptop. (I used the dd command and the QTParted application, but Knoppix also includes Partition Image.)

Another neat trick is that because the read-only DVD is mounted in to a RAM-disk, it behaves as though you can write new data on it. If you notice that there is something missing that you need to use, you can install it. Your changes will all disappear when you turn off the computer though, unless you use the latest whizzy feature to get added to Knoppix: you can use a USB memory stick to make changes to the filesystem on the DVD look persistant. Next time you boot, plug your USB stick in before you put the CD in, and you will be asked if you want to restore your settings. (Click the little penguin button at the bottom left of the screen to see the Knoppix menu, which is where you find the application that sets up your USB key.)

I got a bit carried away with that, and quickly filled up my USB stick with Perl modules. (Actually I think it was mostly full of indexes from the apt-get database and the cpan archive ...) Mysteriously there are some parts of the hard disk that it doesn't let you save, so I couldn't set login passwords for instance, they are reset to nothing at each reboot.

I didn't get to the bottom of why some bits of the filesystem were saved and not others. Like all gadgets, I got bored with it after a while. At least until the next version is ready for me to download!