VERITAS File SystemÖ 3.5 (HP OnlineJFS/JFS3.5) AdministratorÆs Guide (December 2002)

Chapter 6
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6 Online Backup
Introduction
This chapter describes the online backup facility provided with the VERITAS File System (VxFS). The
snapshot feature of VxFS can be used to create a snapshot image of a mounted file system, which becomes a
duplicate read-only copy of the mounted file system. This chapter also provides a description of how to create
a snapshot file system and some examples of backing up all or part of a file system using the snapshot
mechanism.
The following topics are covered in this chapter:
• Snapshot File Systems
• Using a Snapshot File System for Backup
• Creating a Snapshot File System
• Making a Backup
• Performance of Snapshot File Systems
• Differences Between Snapshots and Storage Checkpoints
• Snapshot File System Internals
— Snapshot File System Disk Structure
— How a Snapshot File System Works