If you upgrade Business Continuity Manager to 7.6.1 or later, the default value of the unit to manage the differential data when defining copy groups for TrueCopy will be changed from cylinder to track. Specifically, the default value of DIF UNIT in the following panels will change from CYL to TRK:
Copy Group Attributes For Container (TC) panel
Copy Group Attributes (TC) panel
For details, see the Hitachi Business Continuity Manager Reference Guide.