UNIX System Administration Handbook, Third Edition

2.1 BOOTSTRAPPING

Bootstrapping is the nerd word for “starting up a computer.” The normal facilities provided by the operating system are not available during the startup process, so the computer must “pull itself up by its own bootstraps.” During bootstrapping, the kernel is loaded into memory and begins to execute. A variety of initialization tasks are performed, and the system is then made available to users.

Boot time is a period of special vulnerability. Errors in configuration files, missing or unreliable equipment, and damaged filesystems can all prevent a computer from coming up. Boot configuration is often one of the first tasks an administrator must perform on a new system. Unfortunately, it is also one of the most difficult, and ...