Differential tables are resources shared by the following local replication software products for VSP One Block 85:
- Volume Migration
- ShadowImage, ShadowImage for Mainframe
- Compatible FlashCopy® V2
For Volume Migration, the migration source volumes accept I/O write operations during volume migration. The differential tables are used to track and copy the differential data to the migration target volume. The storage system uses pair tables to manage the differential tables for each pair. When planning for volume migration operations, you can use formulas to estimate the number of differential tables and pair tables that you will need per migration pair.