When you create custom-sized volumes (CVs), you can specify the capacity of each CV. However, rounding will produce different values for the user-specified CV capacity and the actual entire CV capacity. To calculate the actual capacity of a CV, you must use a mathematical formula. These topics explain how to calculate the user area capacity and the entire capacity of a CV.
The entire capacity of a CV or an LDEV consists of the sum of two types of capacity. One type is the user area capacity that stores the user data. The second type is the capacity of all areas that are necessary for an LDEV implementation including control information.
Implemented LDEVs consume the entire capacity from the parity group capacity. Therefore, even if the sum of user areas of multiple CVs is the same as the user area of one CV, the remaining free space generated when multiple CVs are created can be smaller than the free space in the parity group when one CV is created.