HP XP Data Shredder Software - Manual (Page 12)

In this manual, the sum of these two types of capacities is called the entire capacity. This section
explains how to calculate the user area capacity and the entire capacity per CV.
Implemented LDEVs consume this entire capacity from the VDEV capacity without exception.
Therefore, even if the sum of user areas of multiple CVs and the user area of one CV are the same
size, the free space generated when multiple CVs are created may be smaller than the free space
generated when one CV is created.
If the data protection level is set to the enhanced mode on the SATA drive, you must calculate the
entire capacity of CVs in existence, and the entire capacity of CVs in the enhanced mode of the
data protection level. For details about the size calculation, see
“Size Calculation of Volumes (Data
Protection Level is Set to Enhanced Mode on SATA Drive)” (page 15) .
Size Calculation of Mainframe Volumes
To calculate the entire capacity of a CV, use the following formula. For the
user-specified-CV-capacity, specify the capacity of the user area in a CV. The resulting CV capacity
is expressed in megabytes.
(user-specified-CV-capacity + management-area-capacity) Ч 15 Ч capacity-of-a-slot ÷
boundary-value × boundary-value ÷ 1024
To calculate the CV capacity by cylinders, use the following formula. (user-specified-CV-capacity
+ management-area-capacity) Ч 15 Ч capacity-of-a-slot ÷ boundary-value × boundary-value ÷
capacity-of-a-slot ÷ 15
NOTE:
•
The value enclosed in two upward arrows ( ) must be rounded up to the nearest whole number.
•
The user-specified CV capacity is expressed in cylinders.
•
The management area capacity is expressed in cylinders (see “Management Area Capacity
of a Mainframe Volume” (page 16) ).
•
The boundary value is expressed in kilobytes. The boundary value depends on the volume
emulation types and RAID levels (see
“Boundary Value for Each RAID Level” (page 17) ). If the
data protection level is set to the enhanced mode on a SATA drive, the boundary value depends
on the volume emulation types and RAID levels (see
“Boundary Value for Each RAID Level
(Data Protection Level is Set to Enhanced Mode on SATA Drive)” (page 17) ).
•
The capacity of a slot is expressed in kilobytes. The capacity of a slot depends on the volume
emulation types (see
“Capacity of a Slot” (page 18) ).
Size Calculation of OPEN-V Volumes
The methods for calculating the user area capacity and the entire capacity of a CV vary depending
on the unit for CV capacity that the user specifies when creating the CV.
•
If the unit for CV capacity is MB (megabytes):
To calculate the user area capacity of a CV, use the following formula. The resulting user area
capacity is expressed in kilobytes.
user-specified-CV-capacity Ч 1024 ч 64 ч 15 Ч 64 Ч 15
NOTE:
◦ The value enclosed in two upward arrows ( ) must be rounded up to the nearest whole
number.
◦ The user-specified CV capacity is expressed in megabytes.
To calculate the entire capacity of a CV, use the following formula. The resulting entire capacity
is expressed in megabytes.
user-area-capacity ÷ boundary-value × boundary-value ÷ 1024
12 About Virtual LVI/LUN and Volume Shredder