HP XP Racks - Manual (Page 45)

remaining free space generated when multiple CVs are created may be smaller than the free space
in the parity group when one CV is created.
When using RAID Manager, the specified size of CVs is created regardless of the capacity
calculation. Therefore, even if the same capacity size (for example, 1 TB) appears, the actual
capacity size might be different between the CVs created by RAID Manager and the CVs created
by Remote Web Console.
Calculating OPEN-V volume size (CV capacity unit is MB)
The methods for calculating the user area capacity and the entire capacity of a CV vary depending
on the CV capacity unit that is specified when creating the CV.
To calculate the user area capacity of a CV whose capacity unit is defined as megabytes:
ceil(ceil(user-specified-CV-capacity * 1024 / 64) / 15) * 64 * 15
where
•
the value enclosed in ceil( ) must be rounded up to the nearest whole number.
•
user-specified-CV-capacity is expressed in megabytes.
•
The resulting user area capacity is expressed in kilobytes.
To calculate the entire capacity of a CV:
ceil(user-area-capacity / boundary-value) * boundary-value / 1024
where
•
the value enclosed in ceil( ) must be rounded up to the nearest whole number.
•
user-area-capacity is expressed in kilobytes
•
boundary value is expressed in kilobytes. The boundary value depends on volume emulation
types and RAID levels (see “Boundary values for RAID levels” (page 47) ).
•
The resulting entire capacity is expressed in megabytes.
Calculating OPEN-V volume size (CV capacity unit is blocks)
To calculate the user area capacity of a CV whose capacity unit is defined as blocks:
ceil(user-specified-CV-capacity / 2)
where
•
the value enclosed in ceil( ) must be rounded up to the nearest whole number.
•
user-specified-CV-capacity is expressed in blocks.
•
The resulting user area capacity is expressed in kilobytes.
To calculate the entire capacity of a CV:
ceil(user-specified-CV-capacity / (boundary-value * 2)) * (boundary-value * 2)
where
•
the value enclosed in ceil( ) must be rounded up to the nearest whole number.
•
user-specified-CV-capacity is expressed in blocks.
•
boundary-value is expressed in kilobytes. The boundary value depends on volume emulation
types and RAID levels (see “Boundary values for RAID levels” (page 47) ).
•
The resulting entire capacity is expressed in blocks. To convert the resulting entire capacity
into megabytes, divide this capacity by 2,048.
Calculating fixed-size open-systems volume size (CV capacity unit is MB)
To calculate the user area capacity of a CV whose capacity unit is defined as megabytes:
Virtual LUN size calculations 45