How Veritas NetBackup block-level incremental backup works for for Oracle database files

Block-Level Incremental (BLI) Backup extends the capabilities of NetBackup to back up only changed data blocks of Oracle database files. BLI Backup accomplishes this backup methodology using the Storage Checkpoint facility in the Veritas File System (VxFS) available through Storage Foundation for Databases tools. BLI Backup reduces both the time required to complete a database backup and the amount of data transferred during backups. It also allows more frequent backups, resulting in more up-to-date backup images. When restoring from backups, the restore time is increased only by the extra time needed for NetBackup to apply the incremental backups after a full restore completes. However, frequent incremental backups can speed up the database recovery by reducing the number of redo logs to apply.

BLI Backup is particularly useful in a database environment where a database can be hundreds of gigabytes or terabytes. Using traditional backup methods for an offline database backup, any change in the database file - no matter how small - requires backing up the entire database file. Using BLI Backup, only modified data blocks need to be backed up.


To allow BLI Backups, the database must be on VxFS file systems using the Version 4, 5, 6, or 7 layout, and you must have a valid Veritas Storage Foundation Enterprise license. Use the fstyp -v device command to determine the layout version of your file system. See the vxupgrade(1M) manual page for more information.

For information on how to install, configure, and use Veritas NetBackup for Oracle Advanced BLI Agent to perform Oracle database backups, see the Veritas NetBackup for Oracle Advanced BLI Agent System Administrator's Guide.