HDS ShadowImage copy blade

ShadowImage fast-replication copies are incremental copies so only the changed tracks are copied since the last System Level Backup was created. The incremental process reduces the storage processor overhead associated with copying all the source tracks to the target device for each backup operation. The IMS Recovery Expert Log Suspend operation is used to ensure data consistency while ShadowImage commands are executed.

The HDS ShadowImage copy blade does not require the use of SMS or HSM. This reduces the complexity of the backup configuration.

The ShadowImage copy process requires that the source and target volumes be on the same storage processor. The ShadowImage copy blade supports three backup generations. The ShadowImage copy blade allows coordinated FlashCopy® and ShadowImage copy methods to be used. That is, source IMS volumes located on HDS storage processors can use ShadowImage while other source volumes can use FlashCopy fast-replication facilities to perform an IMS System Level Backup operation.

IMS system recovery operations use ShadowImage to restore backup volumes. Application and database recovery operations are performed using DFSMSdss. DFSMSdss will use data set fast-replication, if available. If it is not available, or if the backup background copy process is not complete, it will use host based I/O (slow copy).

When using the ShadowImage copy blade, the target volumes are kept offline. IMS Recovery Expert will perform all the necessary commands to bring the volumes online when needed to copy the volumes to tape or to perform application recovery through DFSMSdss.