There are many methods for backing up data. The methods used are based on factors such as how convenient the backup or recovery process is or the type of data to be backed up.
Online and Offline Backups
Whereas online backups are performed when Exchange services are still running, offline backups are performed when Exchange services are stopped. With online backups and offline backups, Exchange configuration and user data, system state, and file folders containing Windows and Exchange files can be archived. Typically, online backups are preferred because no interruption to Exchange services is encountered.
Administrators can perform basic types of backups with Exchange 2003:
A typical backup plan will include performing full backups on a weekly basis and supplementing them daily with incremental or differential backups. Be sure to store a backup set offsite in case of an unexpected disaster.