The TrueCopy local storage system contains the primary volume (P-VOL) of a copy pair, and the remote storage system contains the secondary volume (S-VOL). When the local storage system accepts a write operation for a P-VOL, the data is written on the P-VOL and then sent by the local storage system to the remote storage system through dedicated data paths connecting the storage systems. Subsequent write operations to the P-VOL are not accepted until acknowledgement is received from the remote storage system for the previous write operation, ensuring that the S-VOL remains synchronized with the P-VOL.
To reduce the overhead associated with remote copy activities and maximize data transfer, the local 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 can be performed using the Command Control Interface (CCI) command-line interface software and the REST API.