Storage

IMS and DB2 for z/OS are data management foundations for many enterprise applications. Many enterprise applications have continuous availability requirements to support transaction processing, Web access, or Service-Oriented Architecture (SOA) applications. The DB2 and IMS systems used to support these applications must be highly available. Fast, non-disruptive backup and data cloning solutions are required to minimize their effect on enterprise applications while providing data recoverability and testing environments. Recovery solutions must be streamlined and fast to minimize application downtime in the event data recovery is required. 

Modern storage systems used to support database systems on z/OS provide storage-based, fast replication facilities that let you quickly copy data without affecting running applications. These copy processes are performed in the storage processor and don’t use mainframe host CPU and I/O resources. Typically, storage administrators have used storage-based fast replication tools such as IBM FlashCopy, EMC TimeFinder, and HDS ShadowImage, but database administrators haven’t effectively used those tools. 

A new class of storage-aware data management tools is evolving that integrates storage-based fast replication facilities with Database Management Systems (DBMSs) to provide fast, non-intrusive DB2 and IMS system-level backup and cloning solutions. These tools simplify backup, recovery, and cloning strategies by using automation to coordinate database system operations with storage-based fast replication facilities. Data copy processes occur efficiently in the storage processors, saving host CPU and I/O resources. 

Storage-aware data management tools provide facilities to link and coordinate application and data management organizations with business continuity and storage administrators. The use of storage-based fast replication to perform traditional data copy functions allows implementation of new backup and recovery methods, simplifies business continuity operations, performs automated cloning operations, and transforms tedious disaster recovery processes into efficient disaster restart procedures. Figure 1 depicts how storage-aware data management tools can be used to integrate application and database administration domains with business continuity and storage administration domains.

Storage-Aware Backup and Recovery 

Some organizations have used Database System-Level Backup (SLB) methodologies for many years as an efficient, effective way to back up database systems. SLB methodologies can involve full-volume dumps or storage-based fast replication facilities. The backups are shipped offsite, where they’re used to provide the foundation for traditional DB2 or IMS disaster recovery procedures. These storage-based backups tend not to be used by DBAs to perform local or disaster recovery operations because it’s difficult to coordinate the data restoration from volume backups with database recovery processes without supporting automation. The complexity associated with using volume backups and the familiarity of using DBMS and host-based copy methods has guided DB2 and IMS DBAs to use traditional image copy backups for local site recovery and disaster recovery purposes. 

New storage-aware backup and recovery tools resolve storage-based fast replication organizational and technology conflicts by allowing storage-based fast replication facilities to be transparently exposed to DBAs. These tools integrate storage-based fast replication to automate and simplify backup and recovery processes. Database system-level backup methods are the foundation for these backup and recovery processes. DB2 and IMS system-level backups performed using storage-aware data management tools have many advantages: 

  • They simplify backup, recovery, and disaster recovery procedures and reduce backup processing and administration costs.
  • Application availability is increased as DB2 and IMS systems can be instantly backed up without affecting running applications. Backup windows are eliminated and application processing windows can be extended.
  • Processing costs are reduced as backups occur in the storage processor without using host CPU or I/O resources.
  • They discover database systems, analyze storage processor configurations, and recommend configuration changes based on the data set layout and recovery requirements.
  • They coordinate storage-based fast replication facilities with database activities to back up database systems. Backups can be validated at backup time to ensure all database resources are contained in the volumes being backed up.
  • System-level backups can be used for multiple backup purposes and save storage resources. System-level backups can support local system recovery, application recovery, database recovery, table and index space recovery, and provide offsite disaster restart support for DB2 and IMS systems.
  • Automated system-level backup offload facilities can archive disk-based backups to tape. The tape archive copies can be used for subsequent local data recovery or for offsite disaster restart and recovery.
  • Data consistency is ensured during the backup process. Data consistency can be maintained across volumes by DB2 when using DB2 Backup System operations or appropriate DB2 or IMS Suspend operations. Storage-based consistency functions also can be used to maintain data consistency during the backup process.
  • System-level backups reduce recovery time. Database systems, application databases, or application table and index spaces are instantaneously restored from a system-level backup using storage processor fast replication facilities while DB2 and IMS recovery operations occur in parallel to the restoration process to minimize recovery time and reduce application downtime.
  • Database system-level backups provide an effective disaster restart business continuity solution that simplifies disaster recovery operations. Disaster recovery can become as simple as restarting from a power failure. 

Storage-Aware Backup and Recovery Requirements 

Storage-aware backup and recovery products that implement a system-level backup methodology require a sophisticated storage integration infrastructure and metadata repository. They leverage storage-based fast replication facilities from mainframe storage vendors such as IBM, EMC, and HDS by integrating storage-based fast replication facilities and transparently exposing them to DB2 and IMS DBAs. 

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