Chapter 1: Backup and Recovery System Requirements Explained

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Overview

A backup is a copy of a defined set of data, ideally as it exists at a point in time. It is central to any data protection architecture. In a well-run information services operation, backups are stored at a physical distance from operational data, usually on tape or other removable media, so that they can survive events that destroy or corrupt operational databases. Backups may be

• Kept at the data center, so that if a storage device, system, or application failure or operational error destroys vital online data, the business can restore its operational records as of a relatively recent fixed point in time. From that point, database logs can restore (nearly) up-to-date business data.

• Moved to one or more alternate sites, to protect against environmental events that destroy an entire data center. With recent backups of operational databases, a business can resume operation quickly when alternative computing facilities are available.

• Made unalterable (for example, copied onto CD-ROM) to provide durable business records for regulatory and business policy purposes when the data is no longer required online.

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