Hacking Ubuntu: Serious Hacks Mods and Customizations (ExtremeTech)

The hacks that I include in this book are the ones that I have found to be the easiest to implement (even if it is a complicated hack), the simplest to maintain, and the most stable of the available options. Having said that, however, any changes you make to your operating system could result in completely screwing up the system. Unless you enjoy reinstalling the operating system or spending hours trying to undo a mistake, I strongly recommend the following precautions:

• Make a backup! Before editing any files or making system changes, be sure to save everything that you cannot afford to lose. Although most hacks are easy to remove, others- like upgrading the operating system-have a point of no return.

  Tip

  See Chapter 3 for a simple system backup script.

• Save system files! Before you edit any system file, make a local copy of it. For example, before editing /etc/ssh/ssh_config, save a copy of the original (sudo cp /etc/ ssh/ssh_config /etc/ssh/ssh_config.bak). This way, you can put back the original file quickly in case you screw something up. I also recommend commenting out undesirable configuration options rather than deleting. (It's easier to uncomment a line to restore functionality than it is to remember what it looked like before you deleted it.)

• Don't play on mission critical systems! If you cannot afford to have downtime, then you should not be trying new tricks on the system. Instead, tinker on a test system, make sure it works, and then apply known-stable changes to your more serious systems.