Live CDs for Demos and Repairs
Much of the credit for live CDs goes to Klaus Knopper, who pioneered the concept with his Knoppix. It is based on the Debian distribution, which is also the ancestor of Ubuntu, and is still one of the best LiveCDs. For information, see knoppix.net.
Bootable CDs are not new … we have used them to install operating systems on computers for years. The innovation of the live CD is that you not only boot from it, but it loads an operating system into RAM so that you can run programs from the CD. You can then try out an operating system without actually having to install it on your hard drive.
First, you need more RAM to run a LiveCD. Many files that would normally stay on a hard drive until needed have to be loaded from the CD into RAM. This means you probably need at least 256 MB of RAM to use a LiveCD successfully.
Because the CD drive is a lot slower than RAM, most applications take longer to load. Other operations may be slower because of the high level of compression to get more programs on the CD. However, once they are loaded, most applications seem almost as speedy as in a normal installation. Some very large programs, like OpenOffice.org, may seem slower because they have files they often have to read from the CD.
If you have only one CD drive, there is another disadvantage in that you cannot usually use your CD since is is being used to load programs from the CD. CD drives are inexpensive, though, so you might consider getting a second one CD or CD/DVD drive, and then one of them could boot the LiveCD and the other could be used for CD or DVD reading and burning.
There are many advantages, though. Besides being able to test out another operating system to see if you like it, you also get to see if it will work with your computer’s hardware.
You can also use a live CD to troubleshoot and repair an installed operating system. There are even problems on Windows computers that are easier to fix using a Linux live CD than using Windows tools.
Take your programs and data with you. If you frequently use computers at cybercafes or an office, you could boot from a LiveCD and insert a USB flash drive. That would allow you to have your own programs and data without bothering anything on the computer you are using.