DFSMS supports the following functions on Enterprise Storage Server® and RAMAC Virtual Array that allow you to copy your data quickly and easily.

FlashCopy®:

FlashCopy is available on the IBM® Enterprise Storage Server (ESS). DFSMSdss uses this function to quickly copy data from source volumes to target volumes that are within the same logical storage subsystem (LSS) or ESS (depending on the ESS hardware). Since copying your data is done very quickly, your applications need only be stopped for a very short time period.

SnapShot:

SnapShot is available on the RAMAC Virtual Array (RVA). This function quickly copies data from source volumes to target volumes that are within the same LSS. SnapShot allows you to copy a specific set of tracks, an entire volume, or a data set. The copy operation is completed with only a few I/Os to the device. There are two kinds of SnapShot copy. Native SnapShot copies data directly to the target device. Virtual-concurrent-copy SnapShot copies data to an intermediate location (where it is logically complete) and then to the target device (where it is physically complete).

Concurrent Copy:

Concurrent copy is a hardware and software solution that allows you to back up a database or any collection of data at a point in time and with minimum down time for the database. The database is unavailable only long enough for DFSMSdss to initialize a concurrent copy session for the data, which is a very small fraction of the time that the complete backup will take. The copy that is made does not include any of the update activity; it is as if the backup were made instantaneously when it was requested. After initialization, DFSMSdss releases all the serialization it holds on the data, informs the user that the initialization is complete so that update activity can resume, and begins reading the data. Concurrent copy is supported on 3990 storage subsystems. Concurrent copy is supported on ESS subsystems in situations where FlashCopy is not available, such as when source and target volumes are in different ESS subsystems.