One of these days you will lose the operating system disk for an important system, and you will need to recover it. This is called a “bare-metal recovery.” The standard recovery method described in many backups products’ documentation is to install a minimal operating system and restore on top of it. This is the worst possible method to do a bare-metal recovery of a Unix system; among other problems, you end up overwriting some of the system files while the system is running from the very disk to which you are trying to restore. The best ways to do bare-metal recoveries for six different versions of Unix are covered in detail in this book.