Home | Previous Page | Next Page   Overview of the ON-Bar Backup and Restore System > Backing Up with ON-Bar > Preparing for a Backup >

Choosing a Backup Level

ON–Bar supports level-0, level-1, and level-2 backups.

Tip:
It is good practice to create a backup schedule that keeps level-1 and level-2 backups small and to schedule frequent level-0 backups. With such a backup schedule, you avoid having to restore large level-1 and level-2 backups or many logical-log backups.

Level-0 Backups

Level-0 backups can be time-consuming because ON–Bar writes all the disk pages to backup media. Level-1 and level-2 backups might take almost as much time as a level-0 backup because the database server must scan all the data to determine what has changed since the last backup. It takes less time to restore data from level-0, level-1, and level-2 backups than from level-0 backups and a long series of logical-log backups.

Level-1 Backups

A level-1 backup takes less space and might take less time than a level-0 backup because only data that changed since the last level-0 backup is copied to the storage manager.

If you request an incremental backup where no previous incremental backup exists, ON–Bar automatically performs the lower-level backup. For example, if you request a level-1 backup but no level-0 backup exists for one of the dbspaces, ON–Bar automatically performs a level-0 backup of that dbspace and a level-1 backup of the other storage spaces.

Dynamic Server

If you request a whole-system level-1 backup and no level-0 backup exists, ON–Bar performs a whole-system level-0 backup. If you request a whole-system level-2 backup but the level-1 backup does not exist, ON–Bar performs a whole-system level-1 backup.

End of Dynamic Server

Level-2 Backups

A level-2 backup takes less space and might take less time than a level-1 backup because only data that changed since the last level-1 backup is copied to the storage manager.

Home | [ Top of Page | Previous Page | Next Page | Contents | Index ]