Understanding DB2 backup objects and failure scenarios

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Data Protection for SAP backs up and restores SAP® database objects.

This graphic shows those database objects for which a backup can be done by using. These objects are DB2 configuration files and DB2 containers, which are handled by DB2 Backup. Offline log files, for which a backup can be made either by using SAP BACKUP or the DB2 Log Manager. For Online log files, there is no backup. — Figure 1. DB2® Backup Objects

Corrupt database: For a corrupted database (caused by user errors or transaction failures), the database can be restored to a specific point in time. Restoring only the database and configuration files can be sufficient for a specific point in time operation. As a result, a backup image of the database and the corresponding DB2 log files are required.
Hardware failure: In the event of a storage hardware failure, the database is typically restored to the most recent point in time. Thus, the most recent database image and DB2 log files are restored. However, the database executable files, SAP system data, and restoring user data might be necessary in the event of a hardware failure. To protect the system against the loss of SAP executable files, user data, or even operating system data, use the IBM Storage Protect™ backup-archive client incremental backup feature. You can use the client to define an include-exclude list of files that to be backed up during incremental backup operation. The include-exclude list is to exclude database container files and offline log files that were backed up or archived by Data Protection for SAP. Example include-exclude list files are provided in the Data Protection for SAP installation directory.
Disaster recovery: For a complete disaster recovery operation, all operating system data must be restored along with the database image, DB2 log files, database executable files, SAP system data, and user data. To help prevent a complete loss of the operating system, use operating system utilities (such as mksysb for AIX®) to run system backups. Such backups are to be done after you install, update, or upgrade the operating system. After these actions, you can start your system from the backup medium. A configured TCP/IP environment and IBM Storage Protect backup-archive client installation is to be included in a base backup to be able to restore all data. Since there is no provision for backing up online DB2 log files that are required for disaster recovery, place the DB2 log directory on a mirrored disk.