When you migrate mainframe volumes, you must determine the total number of required differential tables and pair tables per migration pair. Use the following equation to calculate the required amount of differential tables. Figures are rounded up to the nearest whole number. If you use a volume whose size exceeds 223 GB (262,668 Cyl), the following equation is not necessary because you do not need the differential table.
Total number of the differential tables per migration pair = (X + Y) × 15 / Z
Where:
- X = number of volume cylinders to be migrated. If the volume has been divided by the Virtual LVI function, this value is the number of cylinders in the divided volume.
- Y = number of control cylinders
- Z = number of slots that can be managed by a differential table