Knoppix is not just another Linux distribution. Unlike many Linux alternatives, Knoppix doesnâ€™t need to be installed; everything runs from a CD (called a â€˜Live CDâ€™ distribution). While Live CDs arenâ€™t unique to Knoppix, it is the way the Knoppix CD is packaged that makes the difference. Knoppix includes intelligent hardware detection â€“ it can automatically identify nearly everything on your machine and then make the bet of it â€“ and the CD includes a wide selection of programs, from typical Linux applications through to repair utilities and tools.
I talked to Kyle Rankin, author of Knoppix Hacks about how the book idea was formed, how he chose the contents and some of the things you can do with Knoppix.
A friend of mine works at O’Reilly heard that they were looking for someone to do a Knoppix book for them. Not too long before he had seen me use Knoppix at an installfest to resize someone’s Windows partition and set up Debian in a relatively short amount of time. He approached me with the news and encouraged me to send them a book proposal. I had never written a book before, but I personally used Knoppix a lot, especially as a recovery tool. I thought a Hacks book applied to Knoppix was a great idea so I started jotting down ideas and submitted a formal proposal for the book that was accepted. Add months of furious writing and Knoppix Hacks was born. I started the book liking Knoppix and finished the book absolutely loving it.
What impressed me most is the range and usefulness of the hacks - I immediately felt like trying them out, even if I didn’t want to image my partition. How did you pick the hacks that made it into the book?
Thanks. When writing the book, I realized that you could organize the ways that people use Knoppix into a few general categories: desktop use, a Linux installer, a systems administrator tool, a rescue CD, and as a platform to create your own live CD. We had a discussion about whether to make the book mostly focused on more advanced topics like system recovery, sysadmin hacks, and remastering, but decided that it since Knoppix was used by all sorts of people at many different skill levels, it made more sense to represent all of the different types of use in different chapters. In particular, when I wrote the Linux and Windows repair chapters, I tried to think of all of the different recovery scenarios that I have found myself in, and how I used Knoppix to fix it. My goal was to create a list of common recovery steps that a sysadmin in a jam would reach for before anything else. Along the way I discovered some really clever recovery techniques you could use Knoppix for that I hadn’t known about previously (like Windows registry hacking).
Knoppix is obviously a practical way to do a great many things; can it also be used as a general desktop OS?
Knoppix was actually originally created just to be a portable Linux distribution for Klaus Knopper to take with him to different computers. From the very beginning it was intended first and foremost to be a desktop OS. The excellent hardware detection makes it much easier to take the CD from computer to computer, and there are a number of scripts in place that allow you to keep your settings no matter what computer you are in front of.
What do you do about user storage. Can I use a USB key for example?
Yes, you can use basically any writable media you might have (that Knoppix can detect) to store user files including floppy drives, hard drives on the system, and USB keys. There are a few different scripts included with Knoppix that automate the process of storing data to writable media so it’s really just a matter of a few clicks to save settings. Then you just use a cheat code when you boot Knoppix to tell it to restore your settings the next time you boot. 5. Staying on the topic of alternative storage mediums, is it possible to use Knoppix on DVD, USB Key or smaller storage mediums, like Compact Flash? Knoppix can be remastered and used on a DVD and in fact there are a few Knoppix variants that have done just this. In fact, Klaus Knopper has announced his intention to start shipping a formal DVD version of Knoppix as soon as this summer. Knoppix is pretty large, so the process of stripping it down to smaller media such as a USB key or flash drive can be difficult. Luckily there already are a number of other distributions such as Feather Linux that make it easy to set up and use on a USB key.
Is there any reason why I shouldn’t simply write my Knoppix image to my hard disk and never use the CD ever again?
A number of people have installed Knoppix to a hard drive as a permanent solution over the years, and in fact there is a nice GUI that automates the process. However, Knoppix was designed to be run from CD-ROM and Klaus mixes packages from a number of different Debian repositories. This can make upgrading in the future quite a headache so I generally recommend people to immediately dist-upgrade to Debian Sid if they install Knoppix (and I include a hack in the book that talks about how to do this). Alternatively there are other distributions that make Debian easy to install like Ubuntu and Kanotix that are also much easier to upgrade.
Some of the tools represent what can only be classed as an administrators dream. Image partitioning, copying and repair tools are all on the Knoppix CD. Could you tell us a little more about these hacks and how they can be exploited?
It’s actually pretty amazing how many different administrator tools Knoppix includes. Some of the things that really surprised me were the complete Apache and BIND servers that were included on the CD so in a pinch you could set up a number of different emergency servers. A friend of mine actually used this idea when a webserver of his was hacked into. He needed to be able to serve the pages while not having the server actually be up and running, so he booted Knoppix and served the web pages directly from its Apache server. It’s especially interesting to introduce Knoppix to a systems administrator who is mostly used to proprietary (and often expensive) Windows admin tools. You can use dd or partimage to image disks locally or over the network, you can graphically resize partitions on the fly with QTParted, you can scan systems for viruses and rootkits, perform forensics scanning, wipe hard drives, plus a number of other things all from this single free CD. Also, Knoppix makes for a great sanity check when you suspect hardware is bad. You can not only test the RAM, but you can also test hardware from the CD.
The Knoppix idea seems so obvious - does it surprise you that it’s a relatively recent invention?
Over time there have been a number of different rescue floppies and CDs like tomsrtbt and the old LinuxCare bootable business card, but what continues to surprise me with Knoppix is just how incredibly flexible and useful the CD is. You can use it to demo Linux to a newcomer, fix a broken Windows system, and scan a Linux server for rootkits all from the same CD. There are hundreds of different Live CDs out there, many based on Knoppix, but I’ve found that I keep coming back to Knoppix for day-to-day use just because of how flexible it is.
I’m hoping you have a Knoppix Hacks Volume 2 in the works?
Well, I have actually recently finished a Knoppix Pocket Reference for O’Reilly that should be out in July. As the name indicates it is much more referential and even though it is small, covers a lot of ground that Knoppix Hacks didn’t cover while containing a lot of the sort of Knoppix tips you’d want to carry around in your pocket. As far as a second edition of Knoppix Hacks, Knoppix continues to add interesting functionality (for instance, I can think of a number of really powerful Hacks you can do just with the new UnionFS system in 3.8) so a second edition is a possibility but nothing is officially planned or anything.
Obviously MacGyver is a favourite, but is there anything else you like to watch when relaxing?
What is this ‘relaxing’ you speak of? Actually when I’m not working or writing, I like to watch the Daily Show and have been a long time fan of the Simpsons. I’ve noticed my wife and I have been watching more movies these days than TV shows (probably Netflix has something to do with that). Any remaining free time I have seems to be absorbed by IRC.
Kyle Rankin Bio
Kyle is a system administrator for The Green Sheet, Inc., the current president of the North Bay Linux Users Group, and the author of Knoppix Hacks. Kyle has been using Linux in one form or another since early 1998. In his free time he does pretty much the same thing he does at work–works with Linux.