IN THIS CHAPTER
Doing local backups to removable media
Using rsync for remote backups
Using backuppc for site-wide backups
Backups are spare copies of the files and directories that are found on a computer system, written to and stored on removable media that is preferably stored somewhere other than beside your computer. Doing backups is a time-consuming, but absolutely mandatory task if you place any value at all on the files, e-mail, and other data that you have stored on your computer.
Backups are exactly like auto insurance policies—well, almost exactly, because they're not a legal requirement to own a computer system (in most states). You rarely need them, and you hope that you never do. They are usually just time-consuming and expensive (your time has some value, right?). However, one rainy night when you discover that you've just accidentally deleted your home directory or when a user comes to you and says that they've accidentally deleted your company's personnel records, payroll data, or the source code for your company's products, you'd better have a good answer. The right answer, of course, is, "I'll restore that from backups immediately."
It's hard to think of anything that so thoroughly combines the mundane and mandatory as backing up your data. It's boring. It's time-consuming. And, of course, it's critical. This chapter is oriented toward you as a systems administrator, regardless of how many systems you're responsible ...