This IBM Redbook describes availability procedures for the database of an SAP R/3 4.6B installation that uses DB2 UDB for OS/390 as the SAP R/3 database server. The redbook is one of a series that focuses on SAP R/3 when DB2 UDB for OS/390 is used as a database server.
This redbook reflects the considerable development effort, both by SAP AG and by IBM, that has been focused on the area of database availability due to the reliance on SAP R/3 by customers who expect a high degree of availability, in some cases 24 hours per day, every day of the year.
Since the subject of this book is database availability, we concentrate on the database that applies to this solution, DB2 UDB for OS/390. Much effort was spent on looking at data sharing with DB2 to see how that improves availability of the database, and to investigate how it is defined and used. We also review database administrative activity that must be periodically run, to see how that can be done with as little disruption as possible.
We also investigate the Split Mirror Backup Facility as defined by SAP R/3 and implemented with DB2 UDB for OS/390. A particular area of interest is the minimizing of time to perform a backup, since this regularly scheduled activity can be disruptive. Obviously, no discussion of backup is complete without a discussion of using the backups for recovery, so we address the subjects of full and partial recovery as well.
Our environment included an OS/390 installation on Parallel Sysplex, so we also document specific Parallel Sysplex configuration examples and functions that apply to SAP R/3, and present the results of the limited testing we performed on those functions.