About configuring NetBackup for SAP block-level incremental backups on UNIX

If only a small portion of a database changes on a daily basis, full database backups are costly in terms of time and media. The Block-Level Incremental (BLI) Backup interface extends the capabilities of NetBackup to back up only the file system blocks that contain changed data blocks.

A database BLI backup is done at the file system block level, which means only changed file blocks are backed up. Unchanged blocks within the files are not backed up. The VxFS Storage Checkpoint facility tracks changed blocks in real time. Accordingly, a BLI backup does not need to search the entire volume for the modified blocks at backup time. BLI backup saves time, decreases the amount of backup media that is required, and significantly reduces CPU and network overhead during backups. In addition, BLI backup allows more frequent backups, so backup images are more up to date.

BLI backup is particularly useful for any large databases that are sized in terms of hundreds of gigabytes or terabytes. Most traditional methods for database backup require that any change in the database - no matter how small - requires that the entire database is backed up. With BLI backup, only modified blocks (or file) need to be backed up.