For more information about FlashCopy set-up, see Chapter 9, “Configuring and operating the IBM TS7700” on page 339. For DR testing examples, see Chapter 14, “Disaster recovery testing” on page 769. 

Consider the following points regarding FlashCopy for DR Testing: 

GLYPH<SM590000> Disk cache snapshot occurs to one or more TS7700 clusters in a DR family at the same time within seconds. 

GLYPH<SM590000> All logical volumes in a TS7700T/TS7700C CP0 partition and all logical volumes from CPx kept in cache, are part of the DR-Flash. 

GLYPH<SM590000> Volumes in the TS7700T or TS7700C that are stored in CPx partitions that are migrated to physical tape or cloud are not part of the DR-Flash. They can still be accessed if the LIVECOPY Option is enabled and the logical volume was created before time zero. 

GLYPH<SM590000> Volumes in the TS7720T that are stored in CPx partitions and are migrated to physical tape are not part of the DR-Flash. They can still be accessed if the LIVECOPY Option is enabled and the logical volume was created before time zero. 

GLYPH<SM590000> TS7700 clusters within the DR location should be increased in size to accommodate the delta space retained during the test: 

– Any volume that was deleted in production is not deleted in DR clusters. 

– Any volume that is reused in production results in two DR copies (old at time zero and new). 

– Any new content created by the DR hosts, such as a dedicated volume range used by the DR host. 

GLYPH<SM590000> Automatic removal is disabled within all clusters during a DR test requiring a pre-removal to be completed before testing. 

GLYPH<SM590000> LI REQ  DR Family settings can be completed in advance, which enables a single LI REQ command to be run to start the flash and start DR testing. 

GLYPH<SM590000> DR access introduces its own independent ownership and allows DR read-only volumes to be mounted in parallel to the production-equivalent volumes. 

The following terminology is used for FlashCopy for DR Testing: 

## Live copy 

## FlashCopy 

## DR family 

A real-time instance of a virtual tape within a grid that can be modified and replicated to peer clusters. 

This instance is the live instance of a volume in a cluster that is the most current true version of the volume. It is live production data or the latest instance that is created by a DR host. 

A snapshot of a live copy at time zero. The content in the FlashCopy is fixed and does not change, even if the original copy is modified. A FlashCopy might not exist if a live volume was not present at time zero. In addition, a FlashCopy does not imply consistency because the live copy might be an obsolete or incomplete replication at time zero. Synchronous mode volumes are flashed up to the last successful sync point before time zero. Data after the last sync point can exist, although its validity is based on how much data was written at time zero. 

A set of TS7700 clusters (most likely those clusters at the DR site) that serve the purpose of DR. A total of 1 - 7 clusters can be assigned to a DR family. 

The DR family is used to determine which clusters are affected by a flash request or write-protect request by using the LI REQ  (Library Request command). 

