[Osiris]

Get To Know Linux: Live CD

I have mentioned, many times, various Live CDs to use for giving Linux a try or installing Linux. I have had some feedback asking to explain just what a Live CD is. Some users are hesitent to use a Live CD for fear of deleting their data or damaging their hard drive. My hope is that, upon reading this, your fears will subside and the Live CD will become a useful tool to aid you in your quest to get to know Linux.
What exactly is a Live CD? A Live CD is a CD (or flash drive) that contains a complete and bootable operating system that is run directly from the CD and not the hard drive. There are many types of Live CDs that serve different purposes. There are live distributions for repairing Windows or Linux systems (such as SystemRescueCD). There are live cds for nearly every Linux distribution that allow you to test and/or install the distribution (Ubuntu, Fedora, OpenSuSE, Mandriva, ELive). You can even do stress testing and benchmarking with Live CDs like Inquisitor. Or what about a complete, embedded firewall distribution m0n0wall.
Why Use a Live CD?
The main purpose of a Live CD is to test drive Linux. A Live CD runs directly from the CD and the PCs RAM and does not even need a hard disk to run. Because of this, you can rest assure that a Live CD is not going to alter your hard disk unless you actually choose to install the Live CD onto your drive.
There are many reasons why a Live CD would be preferred. For instance, hardware diagnostics. I have employed Puppy Linux on numerous occassions in order to get information on a piece of hardware or test to see if a piece of hardware is working. I have also used that same Live distribution to run older machines where only certain functions are necessary. Live CDs are also great choices for cafes where you want to start with a clean slate every day. Another great use for a Live CD is when a machine has no mutable storage (a hard drive) and you want to run the computer as a pseudo “dumb terminal” or “thin client”. This would allow users to execute certain tasks so long as they didn’t need to save any work.
But what if you want to save information? For that you can use the flash drive-based Live distributions. With a large enough flash drive the user can also save data as well as run the operating system. If you’re looking for a pre-installed solution Mandriva has the Mandriva Flash Drive which has 6 gigs of free space for data.
One of the best reasons for using a Live distribution, in my opinion, is testing to see if that distribution works well with the hardware you have. I have one particular laptop that, when it comes time to upgrade operating systems, I wind up burning numerous distributions onto CD and running each one of them until one of them can work with the finicky hardware on that machine.
Drawbacks
One of the biggest drawbacks of using a Live CD is the speed. Remember, you are running this from RAM so the amount of RAM the machine has (as well as the speed of the CD drive) will determine how fast your Live CD distribution will run. So a machine with low RAM will run poorly. This isn’t such an issue if you are planning on installing immediately. But using the Live CD on a low-RAM machine will be painfully slow.
The other drawback was already mentioned, unless you are using a flash drive-based Live distribution, you can not save data. If you are only testing the distribution out to see if you like it, that’s not a problem.
Final Thoughts
Live CDs are here to stay. They have many uses and few drawbacks. If you are hesitant to use a Live CD because you don’t want to lose data, you shouldn’t worry about that (unless you accidentally click the installation button and accidentally click through all of the steps to install the operating system.)