The TrueCopy (TC) remote replication software for Hitachi Virtual Storage Platform One Block 20 (VSP One Block) provides a continuous, nondisruptive, host-independent remote data-replication solution for disaster recovery or data migration purposes. Using the TrueCopy software, you can create and maintain mirror images of production volumes at a remote location. TrueCopy remote replication software can be deployed with Universal Replicator software's asynchronous replication capabilities to provide advanced data replication among multiple data centers. In addition, TrueCopy remote replication software can be integrated with the ShadowImage® local replication software to enable robust business-continuity solutions. This lets you create a remote copy of primary site or production data that is automatically updated for executing test and development tasks, or for operations against production data.
The TrueCopy primary storage system contains the primary volume (P-VOL) of a copy pair, and the secondary storage system contains the secondary volume (S-VOL). When the primary storage system accepts a write operation for a P-VOL, the data is written on the primary volume and then sent by the primary storage system to the secondary storage system through the dedicated data paths connecting the storage systems. Subsequent write operations are not accepted by the primary volume until acknowledgement is received from the secondary storage system for the previous write operation, ensuring that the data in the secondary volume stays synchronized with the primary volume.
To reduce the overhead associated with these remote copy activities and maximize data transfer, the primary storage system uses a special write command for TrueCopy remote copy operations. This command transfers the control parameters and the FBA-format data for consecutive updated records in a track using a single write operation. The special write command eliminates the overhead required for performing FBA-to-CKD and CKD-to-FBA conversions.
TrueCopy operations for VSP One Block are performed using the Command Control Interface (CCI) command-line interface software and the REST API.