HP XP P9500 Storage - Manual (Page 43)

Additionally, if the data protection level is set to the Enhanced mode on a SATA drive parity group,
you must calculate the entire capacity of all CVs in existence and the entire capacity of CVs in the
Enhanced mode of the data protection level.
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 (other than Enhanced mode on
SATA drives)” (page 46) ). If the data protection level is set to the Enhanced mode on a SATA
drive, the boundary value depends on volume emulation types and RAID levels (see
“Boundary values for RAID levels (Enhanced mode on SATA drives)” (page 46) ).
•
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 (Enhanced mode on SATA drives)”
(page 46) ). If the data protection level is set to the Enhanced mode on a SATA drive, the
VLL size calculations 43