Chapter 9: Performing System Backups and Restores

Overview

The most important asset on a computer system is the data, which must be protected from a possible disaster. This involves copying the data from the system to storage media—a process called backup—and, when a need arises, copying the data back to the system—a process called restoration or recovery. Solaris offers tools for backup, such as the ufsdump command, and tools for restoration, such as the ufsrestore command.

When you plan to back up a whole file system or all the file systems on a Solaris system, you need to make sure that all the files are copied to the media correctly. To ensure this, you should make the file system or the Solaris system unavailable to users by unmounting the file system or bringing the Solaris system to single-user mode. Because this is inconvenient for the users, in some situations you will want to make a backup without making the file system unavailable to them and just take a snapshot of an active file system. Your backup strategy will affect how easy or difficult it will be to restore the data.

The core issue to think about in this chapter is: how do we make efficient use of the Solaris tools available for backup and restoration? To understand this, we will explore the following three thought streams: backing up unmounted file systems, backing up mounted file systems, and restoring the backups.