Linux Command Line and Shell Scripting Bible. Christine Bresnahan

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      In the early days of Linux, a distribution was released as a set of floppy disks. You had to download groups of files and then copy them onto disks. It would usually take 20 or more disks to make an entire distribution! Needless to say, this was a painful experience.

      Nowadays, with home computers commonly having CD and DVD players built in, Linux distributions are released as either a CD set or a single DVD. This makes installing Linux much easier.

      However, beginners still often run into problems when they install one of the core Linux distributions. To cover just about any situation in which someone might want to use Linux, a single distribution must include lots of application software. They include everything from high-end Internet database servers to common games. Because of the quantity of applications available for Linux, a complete distribution often takes four or more CDs.

      Although having lots of options available in a distribution is great for Linux geeks, it can become a nightmare for beginning Linux users. Most distributions ask a series of questions during the installation process to determine which applications to load by default, what hardware is connected to the PC, and how to configure the hardware. Beginners often find these questions confusing. As a result, they often either load way too many programs on their computer or don't load enough and later discover that their computer won't do what they want it to.

      Fortunately for beginners, there's a much simpler way to install Linux.

      A new subgroup of Linux distributions has started to appear. These are typically based on one of the main distributions but contain only a subset of applications that would make sense for a specific area of use.

      In addition to providing specialized software (such as only office products for business users), customized Linux distributions also attempt to help beginning Linux users by autodetecting and autoconfiguring common hardware devices. This makes installing Linux a much more enjoyable process.

Table 1.5 shows some of the specialized Linux distributions available and what they specialize in.

Table 1.5 Specialized Linux Distributions

      That's just a small sampling of specialized Linux distributions. There are literally hundreds of specialized Linux distributions, and more are popping up all the time on the Internet. No matter what your specialty, you'll probably find a Linux distribution made for you.

      Many of the specialized Linux distributions are based on the Debian Linux distribution. They use the same installation files as Debian but package only a small fraction of a full-blown Debian system.

The Linux LiveCD

      A relatively new phenomenon in the Linux world is the bootable Linux CD distribution. This lets you see what a Linux system is like without actually installing it. Most modern PCs can boot from a CD instead of the standard hard drive. To take advantage of this, some Linux distributions create a bootable CD that contains a sample Linux system (called a Linux LiveCD). Because of the limitations of the single CD size, the sample can't contain a complete Linux system, but you'd be surprised at all the software they can cram in there. The result is that you can boot your PC from the CD and run a Linux distribution without having to install anything on your hard drive!

      This is an excellent way to test various Linux distributions without having to mess with your PC. Just pop in a CD and boot! All the Linux software will run directly from the CD. You can download lots of Linux LiveCDs from the Internet and burn onto a CD to test drive.

Table 1.6 shows some popular Linux LiveCDs that are available.

Table 1.6 Linux LiveCD Distributions

      You may notice a familiarity in this table. Many specialized Linux distributions also have a Linux LiveCD version. Some Linux LiveCD distributions, such as Ubuntu, allow you to install the Linux distribution directly from the LiveCD. This enables you to boot with the CD, test drive the Linux distribution, and then if you like it, install it on your hard drive. This feature is extremely handy and user-friendly.

      As with all good things, Linux LiveCDs have a few drawbacks. Because you access everything from the CD, applications run more slowly, especially if you're using older, slower computers and CD drives. Also, because you can't write to the CD, any changes you make to the Linux system will be gone the next time you reboot.

      But advances are being made in the Linux LiveCD world that will help to solve some of these problems. These advances include the ability to:

      ● Copy Linux system files from the CD to memory

      ● Copy system files to a file on the hard drive

      ● Store system settings on a USB memory stick

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