DB2 9 for z/OS: Backup and Recovery I/O Related Performance Considerations
An IBM Redpaper publication
Note: This is publication is now archived. For reference only.
This IBM® Redpaper provides best practices and I/O-related performance considerations for backup and recovery using DB2® 9 for z/OS®. It describes some guidelines for DB2 for z/OS backup and recovery, then it discusses performance considerations that may be used to predict recovery time, which can be used, in turn, to adjust backup frequencies or methods. This Redpaper has the following sections:
“ Planning the backup strategy” on page 2
This section deals with the series of decisions which a backup strategy involves, beginning on the day that disk and tape hardware are purchased. Configuring the DASD hardware is also the subject of Part 1. At this time some fundamental decisions are made that affects both the probability of a hardware failure and the amount of time that it takes you to recover from that failure. The decisions made at this time also affect the performance of online transaction workloads. Part 1 also explains and contrasts the two major types of backups, image copies and system level backups.
“ Recovery strategies” on page 16
This section presents some recovery strategies for recovering the entire DB2 system to the current point in time after a hardware failure. This part explains the factors that affect the recovery time and how to predict the recovery time. Armed with the knowledge of how long recovery will take, it is easier to develop an effective backup strategy that enables you to achieve the recovery time objectives.
“ Backup strategies” on page 22
This section analyzes hypothetical workload and failure scenarios: we examine a scenario of hardware failure and two scenarios involving programming errors. We examine related recovery to the current point in time and to a prior point in time.
This paper references and builds upon the IBM Redbooks® publication Disaster Recovery with DB2 UDB for z/OS, SG24-6370, which focused on disaster recovery, but also introduced some concepts about FlashCopy® and system level backups. That book was written prior to DB2 9 for z/OS, which added some new features that use FlashCopy and system level backups, and prior to the availability of the DS8000™ . This paper contains a discussion of DB2 9 features and DS 8000 functions.