Oh for crying out loud. It happened again. You were looking for something, when another unfamiliar Linux concept was lobbed at you without explanation.
I remember my frustration with the endless onslaught of terminology and concepts to learn.
This time the horrid topic was Live Linux distributions, also known as LiveCDs, LiveDVDs, or LiveUSBs.
Well, worry not! I’m here to help, and Live distributions are easy to understand. You’ll be an expert in no time.
What Are Live Distributions?
You’ve probably never heard of, or imagined, a concept like Live distributions.
Traditionally, operating systems need installation. During installation, they are copied to a computer’s hard disk. The operating system then runs off the disk for the remainder of its life.
Well, brace yourself. This isn’t always necessary. Many Linux distributions support running from a CD, DVD, or USB thumb drive without prior installation.
I don’t know about you, but I was surprised when I found this out. I had always assumed installation was a necessary prerequisite before using an operating system, but that’s not true.
Linux distributions capable of running, without installation, are called Live distributions (think live as in “Saturday Night Live,” not “No! Please! I want to live!”). You get Live distributions the same way as any other distribution. You download it and burn the ISO image to a disc or extract it to a USB thumb drive, or you purchase it from a website like OSDisc.com.
Years ago, when Live distributions came about, the only reasonable option for using Live distributions was burning them to a CD. USB thumb drives and DVDs hadn’t been invented yet.
Because of this, Live distributions became known as LiveCDs. Technology has since advanced and we now have other options for using Live distributions. But, the name LiveCD still sticks around.
It is quite common to hear LiveCD regardless of whether the distribution is used on a DVD or USB thumb drive. Some sticklers for detail call them LiveDVDs if used on a DVD or LiveUSB if used on a USB, but this is far from uniform practice.
Because of the inconsistency, I prefer to stick with the phrase Live distribution instead of using LiveCD, LiveDVD, or LiveUSB.
Downsides & Limitations to Live Distributions
Let’s start with the bad news.
Any changes made to a running Live distribution are temporary. This is because CDs and DVDs are read-only storage. Software installed and settings changed will not persist between sessions. If you install an add-on to Mozilla Firefox, the next time you restart, the add-on will have disappeared.
Because they are writable, it is technically possible to add data persistence on LiveUSBs, with some distributions. But the current methods for doing this are limited, inconsistent, and prone to problems. In my opinion, it’s not worth it.
Effectively, Live distributions are reset to an out-of-the-box state every time you use it. This makes it impractical for use as your normal operating system.
In addition, because they run from a CD, DVD, or USB thumb drive, Live distributions are slower than their traditionally installed counterparts. If you use a fast USB thumb drive and have a lot of memory in your computer, it’s not too bad, but using a DVD on a computer with limited memory is painfully slow.
Upsides to Live Distributions
Yes, it only works with some Linux distributions. It’s true, data doesn’t persist across sessions. But, it’s a full operating system, that doesn’t require installation, at your fingertips. No files or operating systems are overwritten. There’s no need to mess with partitions. It’s a powerful operating system that needs no setup before starting and leaves no traces after shutting down.
This is very powerful. It allows testing whether a distribution meets your needs and approval before committing to it.
These live distributions also open up several possibilities for computer troubleshooting and repair.
Imagine that your normal operating system breaks for some reason, but you have important files you need to access. Simply insert a Live distribution into your computer, start the computer, and mount the hard drive. You can then access all your files and do what you need to do.
Or, perhaps you need to mess with disk partitions, but can’t have your normal operating system running while you do it. Start your Live distribution and manipulate partitions as needed.
I recently experienced this hypothetical situation firsthand. I had to fix someone’s computer when their operating system would not start. I traced the problem to a corrupted hard disk. Using a Linux Mint LiveDVD, I was able to recover all the files from the corrupted disk and copy them to another computer using their home network. I was then able to fix their corrupted drive, reinstall their operating system, and restore all their files. Without the Live distribution, I wouldn’t have been able to recover their files without purchasing a new hard disk, or expensive recovery software.
A Linux Live distribution saved money, sped up the troubleshooting and repair process, and saved files from being lost forever.
Which Distributions are Live?
Linux has countless distributions, and most support this usage. A comprehensive list of live distributions is available at LiveCDList.com. However, it is quite probable that any distribution you want to try will support this, or have a variant that supports it.
Some distributions, like Linux Mint, only come as Live distributions. Others, like openSUSE, give you a choice to either download a Live version or a traditional version that requires installation.
Most Live distributions include a tool to install the distribution, turning it into a traditional operating system install.
Live distributions aren’t perfect. They are slow and do not keep data, applications, and settings between uses.
But, they are full Linux distributions that run without needing installation. This is a boon to anyone experimenting with distributions or repairing computers.
Be sure to share your favorite Live distributions and any awesome stories about how you use them in the comments below!