Knoppix

Knoppix

Knoppix 7.2 with LXDE
Developer	Klaus Knopper
OS family	Unix-like
Working state	Current
Source model	Open source
Initial release	September 30, 2000 (2000-09-30)
Latest release	7.7.1 / October 27, 2016 (2016-10-27)
Available in	German and English
Update method	APT (front-ends available)
Package manager	dpkg
Kernel type	Monolithic (Linux)
Userland	GNU
Default user interface	LXDE (previously KDE)
License	Free software licenses (mainly GPL)[1]
Official website	www.knopper.net/knoppix/index-en.html

Knoppix (/knɒpɪks/ KNOP-iks), often styled KNOPPIX,^[2] is an operating system based on Debian designed to be run directly from a CD / DVD (Live CD) or a USB flash drive (Live USB), one of the first of its kind for any operating system. Knoppix was developed by, and named after, Linux consultant Klaus Knopper. When starting a program, it is loaded from the removable medium and decompressed into a RAM drive. The decompression is transparent and on-the-fly.

Although Knoppix is primarily designed to be used as a Live CD, it can also be installed on a hard disk like a typical operating system. Computers that support booting from USB devices can load Knoppix from a live USB flash drive or memory card.

There are two main editions of Knoppix: the traditional compact-disc (700 megabytes) edition and the DVD (4.7 gigabytes) "Maxi" edition. Each main edition has two language-specific editions: English and German.

Knoppix mostly consists of free and open source software, but also includes some proprietary software, so long as it fulfils certain conditions.^[3]

Knoppix can be used to copy files easily from hard drives with inaccessible operating systems. To quickly and more safely use Linux software, the Live CD can be used instead of installing another OS.

Contents

The classic Knoppix start-up process

More than 1000 software packages are included on the CD edition and more than 2600 are included on the DVD edition. Up to nine gigabytes can be stored on the DVD in compressed form. These packages include:

• LXDE, a lightweight X11 desktop environment (default for 6.0.1 and later), or KDE 3, a more feature-complete desktop which is the default for 5.3.1 and earlier releases.
• MPlayer, with MP3 audio, and Ogg Vorbis audio playback support
• Internet access software, including the KPPP dialer and ISDN utilities
• The Iceweasel web browser (based on Mozilla Firefox)
• The Icedove e-mail client (based on Mozilla Thunderbird)
• GIMP, an image manipulation program
• Tools for data rescue and system repair
• Network analysis and administration tools
• LibreOffice, a comprehensive office suite
• Terminal server

Hardware requirements

Minimum hardware requirements for Knoppix:^[4]

• Intel/AMD-compatible processor (i486 or later)
• 32 MB of RAM for text mode, at least 128 MB for graphics mode with LXDE (at least 512 MB of RAM is recommended to use the various office products)
• Bootable CD-ROM drive, or a boot floppy and standard CD-ROM (IDE/ATAPI or SCSI)
• Standard SVGA-compatible graphics card
• Serial or PS/2 standard mouse or IMPS/2-compatible USB-mouse

Saving changes in the environment

Prior to Knoppix 3.8.2, any documents or settings a user created would disappear upon reboot. This lack of persistence then made it necessary to save documents directly to a hard drive partition, over the network, or to some removable media, such as a USB flash drive.

It was also possible to set up a "persistent home directory", where any documents or settings written to the user's home directory would automatically be redirected to a hard drive or removable media, which could be automatically mounted on bootup. A single file, knoppix.img, was cached on the rewritable media and used to simulate a file system into which files were written for later use. This allowed the user to transparently write to their home directory.

Union mount support was added in version 3.8.1 through UnionFS. This was later replaced by Aufs in 5.1.0 to improve stability.^[5] The union mount allowed virtual updates to the data on the read-only CD/DVD media by storing changes on separate writable media and then representing the combination of the two as single storage device. The writable media could be memory (ramdisk), a hard disk, USB flash drive, etc. This means that the user could modify the software installed on the Knoppix system, such as by using APT to install or update software. The storage device containing the changes needed to be present whenever Knoppix is started, else only the original data from the disc would be used. While Knoppix would scan available storage devices for a persistent home directory by default, a user could dictate a specific location with a boot option (see below) such as:

home=/dev/hda1/knoppix.img^[6]

By carrying a Knoppix CD and a USB flash drive, a user could have the same environment, programs, settings, and data available on any computer that could run Knoppix.

This functionality was only available through Knoppix 5.1.1 (CD release) or 5.3.1 (DVD release). Subsequently, the Live CD paradigm has transformed into portable operating systems that run on external storage.

Boot options

When using Knoppix as a Live CD, one can use boot options, also known as 'cheatcodes', to override a default setting or automatic hardware detection when it fails. For example, the user may wish to boot into a plain console, or proceed without SCSI support. For this, Knoppix allows the user to enter one or more cheat codes at the prompt before booting. If the user does not enter a cheat code, or does not press any key before the timeout, Knoppix will boot with its default options. For example, to set the language to French rather than the default, one would type:

knoppix lang=fr^[6]

Knoppix is a 32-bit Debian Linux based distro, but recent releases (including the latest version 7.6) have also been equipped with 64-bit kernel on DVD edition, it would be automatically boot up for 64-bit computers, or use boot option, knoppix64 manually in the command-line prompt, while knoppix would boot up the 32-bit kernel. Neither PAE or 64-bit applications are supported by Knoppix, and system memory with more than 4 GB could only be used with a 64-bit kernel.

The DVD edition of Knoppix could also be converted onto USB flash drive with flash-knoppix under Knoppix system, and "the KNOPPIX Live System starts and runs about factor 5 faster from USB flash disk than from CD or DVD!".^[7] Besides that, the experimental UEFI support is provided for USB flash drive rather than DVD media. 32-bit UEFI firmware could only boot up 32-bit kernel, while 64-bit UEFI firmware could only boot up 64-bit kernel. The text interface for UEFI is similar with it for BIOS, one could also press key F2 and F3 to inquire information on boot options.

Popularity

Knoppix was one of the first Live CD Linux distributions to gain popularity.^[8] There are several factors that contribute to the popularity of Knoppix:

• Knoppix was one of the first Live CDs available, and is known as the "original" Debian-based Live CD
• Its extensive hardware detection allows most systems to start Knoppix without any configuration
• Its ability to automatically connect to most kinds of networks
• Its utilities for system repair and troubleshooting

Knoppix works on a fairly large number of PCs or laptops, but not all. The automatic hardware detection cannot cope with all hardware, and sometimes the drivers used will not be optimal. Knoppix has difficulty recognizing some cards made before 1998, or motherboards with a BIOS made before 2002. (In some cases, manual configuration with codes entered at boot time can overcome problems with automatic detection.)

If a PC does not have enough RAM to run KDE and other included programs, the legacy Knoppix (earlier than 6.0) boots up a very limited twm session instead. The only window running in the twm session by default is xterm.

Versions

As of April 2008, from version 4 up until 5.1.1, Knoppix has been split into a DVD "maxi" edition (with over 9 GB of software), and a CD "light" edition, both developed in parallel.^[9][10]

The table (to the right) shows the version history of major releases.

The KNOPPIX 6.0.1 / ADRIANE 1.1 is a CD-edition again, and a complete rebuild from scratch. LXDE as default desktop and a very reduced software collection in order to easily fit on CD.^[11] No further development is being done of the traditional 5.x versions.

The KNOPPIX 6.2.1 release has both CD and DVD editions, and the ADRIANE 1.2 only has a CD-edition.^[12]

Derivatives

Adriane Knoppix

Knoppix 6.7

Adriane Knoppix is a variation that is intended for blind and visually impaired people, which can be used entirely without vision oriented output devices. It was released in the third quarter of 2007 as a Live CD. Adriane Knoppix is named after Adriane Knopper, the wife of Klaus Knopper, the developer of Knoppix. Adriane has a visual impairment, and has been assisting Klaus with the development of the software.^[13] The name Adriane is also a backronym for "Audio Desktop Reference Implementation And Networking Environment".

Adriane Knoppix is intended not only for the blind but also for beginners who don’t know much about computers. It uses the SUSE Blinux screen reader with a phoneme generator and speech engine for normal output.

Other variations

Knoppix family tree

• Damn Small Linux, a Live CD, just over 50 MB. It is designed to run graphical applications on older PC hardware - for example, machines with 486/early Pentium processors and very little memory.
• Dreamlinux, a Brazilian distribution branched off from Morphix, centers on ease of use and graphics performance.
• Kali Linux, a live CD/USB distribution now based on Debian. It is a rewrite of BackTrack, which was based on Knoppix. Like its predecessors, Kali is designed for digital forensics and penetration testing. BackTrack itself merged the Auditor Security Collection and WHAX distros.
• Kanotix, a live distribution now based on Debian.
• KnoppMyth, a distro that attempts to make the Linux and MythTV installation as trivial as possible.
• Musix GNU+Linux, specifically for musicians.
• Poseidon Linux, a widely acclaimed distribution specifically geared for the scientific community.
• Quantian, for numerical and quantitative analysis.^[14]
• KnoppiXMAME, designed for playing MAME videogames
• PelicanHPC for clustering
• VMKnoppix for VM tools
• TechUSB an automated computer distro produced by RepairTech, Inc.

Unmaintained projects

• Auditor Security Collection, intended to test the security of networks (merged into BackTrack)
• ClusterKnoppix, which uses openMosix
• Feather Linux, 128 MB image with Linux 2.4, works as a Live CD and Live USB
• Kaella, the French translation of Knoppix. The most recent release is 3.2, from September 19, 2007.
• Kurumin, in Brazilian Portuguese

See also

• Comparison of Linux distributions
• Debian Live
• Iskolinux

Notes

Books

• Granneman, Scott (2005). Hacking Knoppix. Wiley. ISBN 978-0-7645-9784-8. 
• Hentzen, Whil (2007). Knoppix Explained. Hentzenwerke. ISBN 1-930919-56-5. 
• Rankin, Kyle (2004). Knoppix Hacks. O'Reilly. ISBN 978-0-596-00787-4. 

News article

• Distrowatch.com interview with Klaus Knopper (2002)

References

External links

Wikibooks has a book on the topic of: Knowing Knoppix

• Official website
• Knoppix at DistroWatch