IMS Recovery Expert and storage system integration

IMS Recovery Expert leverages storage system capabilities and fast-replication products to perform backup and restore operations on behalf of the IMS system. Using storage-based fast-replication to copy data allows IMS systems to be backed up instantaneously without using host CPU and I/O resources.

IMS system and database recovery operations are expedited by allowing data to be restored using storage system services while IMS recovery operations are performed in parallel. Some storage-based fast-replication products used to support a IMS Recovery Expert System Level Backup approach include: IBM® FlashCopy®, EMC TimeFinder and Hitachi Data Systems (HDS) ShadowImage.

IMS Recovery Expert integrates storage-based fast-replication facilities with IMS backup and recovery processes through the use of a Data Copy Manager. The Data Copy Manager is a software component used to translate logical database backup and restore requests into physical storage system fast-replication facility requests. It uses the IMS Log Suspend operation or storage-based consistency functions to create a dependent-write consistent copy of the IMS data. The Data Copy Manager invokes appropriate volume and data set fast-replication facilities to leverage the underlying storage system capabilities. These requests copy the data on behalf of the IMS systems using storage system facilities. The Data Copy Manager separates IMS logical backup and restore operations from the physical backup processes. This allows new data copy methods and features to be integrated into the IMS Recovery Expert infrastructure easily.

The IMS Recovery Expert Data Copy Manager integrates with specific storage system services and fast-replication facilities through the use of copy blades. A copy blade is a logical grouping of data copy services that can be invoked to drive specific storage hardware and software facilities using appropriate application programming interfaces. Copy blades invoke specific storage system copy services like storage-based consistency functions and drive fast-replication methods to backup and restore IMS data on behalf of the IMS system. Copy blades are used to copy data at a storage volume level and at a data set level. IMS Recovery Expert supports the following copy blades:

  • IBM FlashCopy
  • IBM DFSMSdss
  • EMC TimeFinder
  • HDS ShadowImage

Figure 1 depicts the IMS Recovery Expert Data Copy Manager and its use of copy blades.

Figure 1. IMS Recovery Expert Data Copy Manager interaction with copy blades
This figure shows a box that identifies the fast replication backup and recovery processes that can be invoked by the IMS Recovery Expert Data Copy Manager. They include IBM FlashCopy, IBM DFSMSdss, EMC TimeFinder, and HDS ShadowImage.

The copy blade and copy method used to perform IMS backup and restore operations are specified in the Backup Profile Options (see Setting backup defaults and defining IMS systems and data sharing groups). System Level Backup defaults should be set in consultation with your storage administrator. Copy blade usage specifications can be overridden to accommodate specific IMS System Level Backup requirements when creating or updating a System Level Backup profile (see Creating and maintaining System Level Backup profiles).

After the copy blade, copy method, and data consistency control mechanisms are specified in the backup profile, then IMS Recovery Expert will drive appropriate data copy services and fast-replication facilities through its respective copy blade interfaces to perform IMS backup or restore operations.