Using NetBackup for SAP with Snapshot Client to back up large databases
Veritas recommends that customers with production databases back up their environments on a daily basis. This daily backup often is not feasible for databases of a size between 100 GB to over 1 TB.
This issue exists due to the following concerns:
Server performance. The backup process for large databases can cause severe performance problems because the process consumes the database server's resources. CPU time, the system bus, the I/O bus, hard disk controllers, and volume controllers become saturated. As a result, online use of the SAP system is limited and system performance is unpredictable during the backup.
System availability. Traditionally, backup activities were carried out when there was little or no system activity. This time window usually occurred at night. In today's production environments, which require little or no system downtime, this window is small, if one even exists.
Network performance. Instability and further performance loss may be experienced with a backup of large databases from the production host and over the network.
NetBackup for SAP with Snapshot Client supports split mirror backups. Split mirror backups are the recommended backup method for large databases because these backups overcome the preceding concerns.
In SAP environments, the Snapshot Client technology supports the following major backup strategies:
Off-host backup, which offers more performance. It offloads database backup activity and CPU cycles from the production host to the backup host. Thus, it improves the performance of the production environment.
Snapshot backup, which requires no downtime of your production system. SAP supports both offline split mirror and online split mirror backups. In an online split mirror backup, the production database remains available for user transactions. The need for backup windows is eliminated and 24/7 uptime functionality is provided for continuous business transactions.
(UNIX or Linux) Block-Level Incremental (BLI) Backup. BLI backups decrease the amount of backup media that is required for incremental backups and to significantly reduce CPU and network overhead during backups. BLI, may not be used for incremental backups with SAP with RMAN.
Split mirror backups. Because the mirrors are split from their standard devices and mounted on the backup server, the backup does not overload the network. The backup is run on the backup server without affecting the network.