Many Linux® distributions have been designed as so-called "LiveCDs", which are CDs that can be directly booted into available Linux systems. Contrary to the "rescue mode" boot options that are available in most widely used distributions, these LiveCDs are designed to provide a complete set of tools that can be used when booted from a CD, some of which are General, some are highly specialized. David Mertz introduces this rapidly growing branch of the Linux market. The Linux LiveCD distribution has been around for a number of years, but the number of such releases has increased several times in the last year or two. Most of today's dedicated LiveCDs originate from the Knoppix distribution of LinuxTag, which is a very successful release. The novelty LiveCD distribution -- generally similar to the new Linux distribution -- wraps different software sets for different user groups, and, in order to embody the ideas of their creators, they also wrap fine-tuning configurations and settings. detail. Currently, there are dozens of available LiveCD distributions, even though there are not hundreds of them; obviously, I can't cover all of them in this article. The most popular LiveCD may be a general-purpose office software package specifically designed to show Linux to new users. However, there are other more specialized distributions, such as system clusters, rescue CDs, firewalls, or security tools. In many cases, more specialized distributions will be smaller because they discard most of the common tools.
Booting Linux from CD
In this article, I introduced four common general-purpose distributions: Knoppix, Slax, Mepis, and GoboLinux. However, although in most cases the last release is a general-purpose distribution for office/network/games, its creation is largely to demonstrate some novel ideas about file system design. I also introduced three more specialized LiveCDs: Feather Linux is generic, but very small; EVMix is based on StrongBox and introduces most of the dedicated software for the EVM2003/Open Voting Consortium project, which I am working on; IPCop is another A small LiveCD dedicated to creating Linux-based firewalls. For these distributions, most of them will be described in their respective chapters. However, here I will give a short comment on IPCop. I am excited to use this 22 MB compact ISO to experience a small, dedicated Linux LiveCD. Unfortunately, I was a little disappointed when I tried to boot IPCop; it was not a problem with the release itself, but my expectations. IPCop is only a nominal LiveCD distribution -- although it does boot into a Linux system, the only thing you can do there is to install the system on your hard drive. In this regard, IPCop is similar to any other installable Linux distribution -- most of those distributions also allow you to choose a minimal shell for management. The screenshots in IPCop are interesting, but when I found out that I needed to use my hard drive, I felt that more in-depth testing was beyond the scope of this review. My hunch is that there are many other "LiveCDs" that are advertised as well. By the way, in this review, what I am looking for is something that is obvious or easy to do -- indeed, except for what I am trying to accomplish, other things are possible. My special comments include whether a release can easily save the configuration between the two bootstraps, or whether it can be installed on the hard drive. I believe that as long as I put in enough physical labor, I can do those things in all the distributions, but I am looking for important menu items or instructions to perform those actions. Knoppix 3.4
Knoppix is the most famous LiveCD distribution, so as a basis, first research it. Knoppix 3.4 (2004-05-17) compresses as much content as possible onto a single CD, resulting in a 690 MB ISO image (must buy a 700 MB CD-R instead of 650 MB). As you can see from its size, Knoppix bundles a large number of tools, both for developers and for office use. The tools I've studied are currently popular, but not the bleeding edge: Linux kernel 2.4.26; KDE 3.2.2; OpenOffice.org 1.1.1; Gimp 2.0; Python 2.3.4c1. Knoppix tends to add repetitive programs, which can be confusing for new users: there are ten text editors, which one should I use? Should I use Mozilla or Konqueror for browsing? On the other hand, those who are experienced users are very happy to use; Knoppix insists on using OpenOffice.org as its office suite, and has abandoned KOffice in some distributions. You can direct Knoppix directly, and you don't need any user events to get a KDE desktop that you can use. All of my hardware (on the old machine a few years ago) was properly identified, including my 1280x1024 flat panel display and the pattern that matched my nVidia TNT2 graphics card. The default user is knoppix, but I found that su can be executed without a password - perhaps a compromise between security and user friendliness. You only need to execute passwd to solve this problem, because there should never be an account without a password in the system. The window managers used by all of the generic distributions I tested were KDE (actually, the versions were 3.2.2). There are some differences in configuration details, such as which icons are placed on the panel, which theme is selected, and which click mode is used (click/double click). I don't like Knoppix's choice: click, Keramik theme; but this is purely a personal issue and can easily change. Knoppix also has some other window managers attached, but switching between them seems to break the X11 configuration. For more functional issues, Knoppix introduced an excellent and eye-catching "Save Knoppix Configuration" tool. You can save the settings to a floppy disk or hard disk partition as you wish: such as home directory files, network settings, X11 configuration, printers, and more. Knoppix also automatically mounts all of my hard disk partitions to the desktop, including the HPFS partition on the OS/2 desktop for testing. There are some options for "Install Software" on a running system, but in addition to this limited list, if I try to add another application, apt-get will point out the installation directory read-only error (not obvious to me) Other ways to solve this problem). Contrary to some distributions, Knoppix does not provide an important option to install itself on a hard drive. Mepis 2004
Mepis is a release similar to Knoppix, but it has a dual purpose, either as an installable distribution or as a LiveCD. Like Knoppix, Mepis is also an almost full CD, and in fact it comes with an extra second CD (not directly available). The toolset on Mpeis is mostly the same as those on Knoppix. LiveCDs are considered less for developers and more for office users. For example, LiveOffice includes both OpenOffice.org and KOffice; however, there are very few editors and development IDEs used by programmers. Contrary to Knoppix, Mepis introduces a very good application for installing itself to a hard drive, but lacks the tools to save the LiveCD configuration and the tools to dynamically install additional software while the LiveCD environment is running. True, Mepis' goal is to allow you to experiment before installing, rather than creating a lightweight runtime environment that doesn't require any permanent installation at all. However, the unmodified Mepis LiveCD environment is already very useful, so you can easily save your modified documents or files to other media. Mepis does not automatically mount all the hard drive partitions it finds, but has an icon on its desktop to mount the partition (no need for the user to know the parameters of the mount command). Like Knoppix, Mepis can properly mount my HPFS partition (read-only) and ext2/3 partition (read/write). The boot order of Mepis is slightly different from Knoppix. A better aspect is that Mepis gives you a navigable article menu to choose the kernel version (I tested 2.6, but 2.4 is also available). The ability to choose screen resolution and some other configuration options (also required) is difficult to say. All are given in the form of a friendly scrollable menu, but Knoppix doesn't need to ask for it at all. On the other hand, most of the rest of the distribution assumes that I want to run X11 at a resolution of 1024x768 instead of 1280x768 -- I would rather choose it myself than let the CD mistake it. A minor problem in Mepis is that the passwords for the root and demo accounts it sets are not displayed during the boot process and are not recorded in the top-level README file. I only tried a few times and guessed that the root password is "root", but this is guessed after all.