Backup Exec includes three methods for backing up databases: Full, Differential, and for SQL 2005 or later, Full Copy-only. The full method backs up the entire database including all system tables and filegroups. The differential method backs up only the changes made to the database since the last full backup. The copy method works in the same manner as the full method, except that it does not affect future differential or log backups.
A differential backup is smaller and faster than a full backup, so differential backups can be run more often than full backups. Because differential backups allow the restore of a system only to the point that the differential backup was created, you should also create multiple log backups between the differential backups. Using transaction log backups allows you to recover the database to the exact point of failure.
Consider using differential backups when only a relatively small amount of data changes between full backups, or if the same data changes often. Differential backups may also work well in your environment if you are using the simple recovery model and need backups more often, but cannot spare the time to do frequent full backups. If you are using the full or bulk-logged recovery models, you can use differential backups to decrease the time it takes to roll forward log backups when restoring a database.
If you want to run database backups only, instead of a mix of database and log backups, and you are not running SQL 7.0, use the simple recovery model for the database so that the transaction log is automatically truncated when a checkpoint occurs in the database. This helps prevent transaction logs from becoming full since with other recovery models the logs are not cleared after a database backup.
If you want to run database backups only, and are using SQL 7.0, use SQL Enterprise Manager to enable the database option truncate log on checkpoint for each database you are backing up. Enabling this option causes the transaction log to be automatically truncated whenever a checkpoint occurs in the database.
To back up SQL databases
To select SQL data from local or remote selections, click the domain name icon or icons that contain the SQL installations, and then click the actual Windows computer icon that contains the SQL installation. If you are using a cluster server, make backup selections from the virtual server.
Whether you make SQL database selections using the Windows domain, Active Directory, DNS names, or IP addresses, you must use the same method when making full, differential, and incremental backups of your SQL databases. For example, do not make full backup selections of your SQL databases using the Windows domain, and then make incremental or differential selections using an IP address.