FLOSS Friday: Live CDs and Knoppix
I’ve been a Linux user for 13 years. In that time, Linux has grown from being a plaything of hobbyists to becoming an enterprise-ready operating system capable of competing with the likes of AIX, HP-UX, Solaris, and Microsoft Windows. One way that early Linux promoters used to increase interest in Linux was to produce live CDs. A live CD is a CD that boots to an operating system that doesn’t rely on any other storage to become a fully operational machine. The very first Linux distribution offered in Live CD form was Yggdrasil Linux, way back in 1992-1993. Think about using 1x CD drives on a 386dx running at 33Mhz trying to bring up a full GUI based desktop and you’ll realize why those first forays into live CDs didn’t take the world by storm. Fast forward ten years, to the halcyon days of 2003, when Knoppix was unleashed upon the world by Klaus Knopper [cite].
Knoppix was built from the ground up to not merely boot the operating system to a bare shell prompt, oh no. It was designed to poke and prod your hardware to do its darndest to be up, running, and fully available by the time you see a pretty graphical desktop environment. It’s entertaining just to burn a CD or DVD image of the thing to watch how much stuff it finds on your machine to make use of. Hard drives are scanned and shown via icons (nothing is modified unless you do so, however), portable storage is shown, networking is started if possible, sound is auto-configured (and you know its working because the startup sound is a female voice saying “Initiating startup procedure”), and all of the things that nay-sayers whine about are simply done for you automagically. To steal a line from the Mac fans, “It Just Works”.
OK, you’re still not convinced, why bother with Knoppix (or any other live CD)? Why download a 700Mb iso file for CD or 2+Gb iso file for DVD to get Linux? I’m glad you asked. Here are just a few reasons:
- Privacy. Boot a CD, do anything you want, shut down, and all evidence of your actions are gone.
- With just an optical disc and a USB stick, every computer becomes “your” computer. The latest versions of Knoppix let you save preferences and files to USB to retrieve once you’ve booted. Viruses? What viruses?
- Rescue mode. Here’s where you can be the hero of the hour. Boot Knoppix, make necessary fixes to a sick machine’s hard drive, reboot, and you’re gonna get some major love.
- Play mode. You’ve heard about Linux, but don’t want your highly tweaked main operating system to be destroyed. Boot Knoppix and see what everyone is raving about. Boot some other OS other than Linux. Return to your “normal” computer with a simple Ctrl-Alt-Delete.
- Appliance mode. Besides Knoppix, there’s tons of specialty live CDs that are tailored for audiences such as Tivo like video recorders, music and sound creation and editing, high end 3-d graphics, games, web publishing, and on and on. Let others do the hard work of combining operating systems, libraries, and applications. All you have to do is plop in a disc, fire up the machine, and start using.
- Test mode. Booting a live CD gives you another operating system to run diagnostic tests on hardware, whether hard drive, memory, CPU, or something else. Your hardware vendor blames the OS? Tell ’em it’s time to give you an RMA on that dead whatever.
To give you an example of the power of the live CD, the Ubuntu folks decided that their install CD would actually be a live CD. That is, unlike RedHat, where you have to get a special live version, Ubuntu lets you use their single CD to boot immediately to a running OS. If you like it, you can perform an install from this running image. Reboot, and the same computing environment you were using from CD is now safely tucked onto your hard drive. How awesome is that?
For those of you who can’t escape the Windows world, there is an option: live CD building tools. One famous exampe is Bart PE. Unlike the free software Linux world, you can’t just download Windows live CDs (that would be what we in the tech world call “Illegal”). Rather, you download software that lets you build a live CD ISO file by using data from your own Windows install CD. I’ve had good luck with one called Ultimate Boot CD for Windows.
Have I used live CDs? You betcha. I’ve done Ubuntu installs, I’ve tried out other flavors of Linux, I’ve rescued a few Windows machines from the brink of death. In the last few months I’ve been using Knoppix to diagnose network configurations with blade servers my team is working with. Having a self-contained OS + complete set of diagnostic tools of all kinds makes it dead easy to figure out where things are Going South.
So, you’ve bought into my sales pitch, and you wanna get you some of that there live CD. Here’s some resources to get you started:
Knoppix Home Page – http://www.knoppix.net/
Knoppix DVD Image Torrent – http://torrent.unix-ag.uni-kl.de:6969/
Knoppix Official Mirrors – http://knopper.net/knoppix-mirrors/index-en.html (Pick a .edu for high speed download when on campus)
DistroWatch’s Live CD List – http://distrowatch.com/dwres.php?resource=cd (A static list with background info)
The LiveCD List – http://www.livecdlist.com/
(More distros than you can shake a stick at, with rankings to give you some hope of finding something you want)