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Live CDs Part IV: Specialized live CDs

July 5, 2006

This article was contributed by Michael J. Hammel

See the previous articles in this series: Part I, Part II and Part III.

The last two sets of live CDs each fell into one of two broad categories: desktop replacement or small footprint. Desktop replacement options try to be all things to all people while small footprint CDs are designed for lower end hardware or as the basis for embedded or small system computing.

This time around the set of three live CDs is more specialized, targeting a smaller niche of users. This is the ultimate use of live CDs - filling a special purpose that can't be fulfilled easily by more general purpose solutions. While the niche may be smaller, it doesn't mean the target audience is small. For example, with a games CD your audience could be quite large.

Games KNOPPIX

This special purpose CD is simply a remastered KNOPPIX LiveCD. Games KNOPPIX adds an extra set of games to the base KNOPPIX collection. It doesn't appear to complain about a lack of special purpose hardware and most of the games worked out of the box even though the test hardware did not support 3D acceleration.

I tried a number of the games, though in general I'm not much of a game player. The complete list of games is on the web site. Enigma has great graphics and an interesting Breakout-like concept. There are both full screen and windowed games, text and graphical games and arcade and 3D games. There are also demos of some non-GPL games, such as Marble Blast Gold, Mutant Storm and Space Tripper but most of the games are freely available versions.

GLTron and UFO were the only disappointments but that should have been expected since no hardware acceleration was available for the OpenGL based games.

The web site is light on useful information other than providing a list of the games provided. Remastering this CD is not covered (unless you follow the outlines for remastering a KNOPPIX CD) and at least one game requires you to get permission from the author to do a remaster if the CD will be sold commercially.

As an end user I'd like to see a CD like this one that pulls the unnecessary applications from KNOPPIX and adds a front end that lets me choose the games through a nice UI instead of a buried desktop menu.

Cleanliness:	7
Originality:	6
On Target:	5
Extensibility:	1

Ultimate Boot CD

The Ultimate Boot CD boots into a text based window of options, all accessible via the function and numeric keys on the keyboard. Each option boots the kernel a different way and runs a variety of tests, including tests against the CPU, memory, hard disk and peripherals.

Tests and tools include CPU and memory tests, partition management, CPU and graphics benchmarks, boot disks for recovery operations and system identification tools. Not all of the tools and tests run under Linux so this CD isn't a true Linux only solution. Tests like memtest86 run under DOS so they can get full control of the CPU without the context switching and memory management that Linux would need.

Hard disk tests are manufacturer specific. There are tests for Maxtor, Seagate and Samsung drives. Most of the filesystem tools are Windows specific and of little value to managing your Linux partitions. This is true, too, of the antivirus tools.

Multiple boot disks are provided, including the FreeDOS and OpenDOS open source systems as well as Tom's Boot Disk, BasicLinux, RIP and Trinux for Linux users. Each of these can be used for recovery of hard disk based systems that are failing to boot.

The Ultimate Boot CD allows user defined tools to be added. There is a help screen explaining how to get more information on how this can be done, which makes the CD very customizable.

Overall, this CD is well planned and implemented. It isn't flashy and don't expect a desktop environment. But do expect a large number of very useful tools for diagnosing computer hardware.

Cleanliness:	9
Originality:	9
On Target:	9
Extensibility:	8

KnoppMyth

KnoppMyth, also based on the KNOPPIX live CD, is designed as an easy to use version of MythTV. MythTV is an open source PVR (Personal Video Recorder). The design of MythTV allows users to have a separate backend server to record and manage videos, music, pictures and other features while using a remote frontend system to access the server. What KnoppMyth does is provide either a combined backend/frontend configuration for standalone use or allow a frontend system to connect to an existing backend server.

The live CD boots into a text based main menu where options include running the live CD as a frontend system or installing the live CD to a disk. I selected running the frontend only. After configuring the MythTV database access information and telling the system to use DHCP, the KnoppMyth CD booted directly into the MythTV frontend menus. MythTV is a graphical application running under the X Window System. KnoppMyth did see the Via graphics hardware at boot time and loaded the Via kernel and X video drivers.

An extra menu option not found on the stock MythTV distributions is available from the main menu and is titled "KnoppMyth". This allows the user to backup their configuration, say to an NFS mounted partition or burned to a DVD. Other than that the user interface for the KnoppMyth frontend is just like the stock MythTV distribution. Unfortunately, I was running an older version of the backend MythTV server on the test network. The older server used protocol version 15 while the frontend used 26. So the backend and frontend could not communicate and no further tests could be run.

KnoppMyth is exactly what it is intended to be: an easy to use MythTV system based on a live CD. The menu interface is much simpler to use than a standard desktop which makes this an ideal consumer electronics solution. But the incompatibility with older MythTV backends is a problem. There is nothing on the web site about this unfortunately.

The system loads what looks like every possible video display kernel driver along with the appropriate Via kernel and X drivers. Had I been able to connect to the backend server, video display should have benefited from the hardware MPEG decoding available in the test hardware. Like KNOPPIX, KnoppMyth uses the XFree86 distribution instead of the newer X.org distribution.

The CD is meant as an end user distribution and not intended as a customizable solution. Therefore no information is provided on the web site on how to extend the features of this live CD.

Cleanliness:	9
Originality:	9
On Target:	9
Extensibility:	0

Summary

Over the past 4 articles you've seen a variety of ways that a live CD can be used. While there are literally hundreds of freely available live CDs, the choice of which to use is completely personal. Desktop versions abound, but niche solutions are also available to help you with whatever project you have in mind.

For developers, understanding how a live CD is put together is the first step in understanding some of the issues involved with small system computing. If you need to squeeze a kernel and root filesystem down to fit on a storage limited hand held, then understanding how live CDs make use of SquashFS and UnionFS will get you started. From there, there is no end to where you can go.

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