No matter how reliable your hardware and electrical supply are, or how sure you are that you'll never accidentally erase all your work, it's just common sense to keep backups of your files. Backup strategies differ in ease of use, speed, robustness, and cost.
Although we'll discuss different types of archives below, here's a quick summary of the file extensions associated with the different utilities:
| Extension | Utility |
|---|---|
| .tar | pax or tar |
| .cpio | pax or cpio |
| .gz | gzip or gunzip |
| .tar.gz or .tgz | tar -z |
| .z or .F | melt |
No matter how robust a filesystem is designed to be, there will always be situations in the real world where disk corruption will occur. Hardware will fail eventually, power will be interrupted, and so on.
The Power-Safe filesystem is designed so that it should never be corrupted; you'll always have a complete version of its data. For more information, see “Power-Safe filesystem” in the Filesystems chapter of the System Architecture guide. However, it's still a good idea to back up your data.