HP XP P9500 Storage User Manual

Page 45

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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

boundary value

depends on volume emulation types and RAID levels (see

“Capacity of a

slot” (page 47)

).

The CV capacity recognized by hosts is the same as the CV capacity calculated by the above
formula.

If block is selected as the LDEV capacity unit in the Create LDEVs window and dialog boxes,
the window and dialog boxes correctly show the calculated LDEV capacity. However, if MB,
GB, or TB is selected as the LDEV capacity unit in the Create LDEVs window and dialog boxes,
the capacity values shown might have a margin of error due to unit conversion reasons. If you
need to know the exact LDEV capacity, select block as the capacity unit.

The resulting entire capacity is expressed in blocks. To convert the resulting entire capacity
into megabytes, divide this capacity by 2,048:

Calculating the size of a CV using Enhanced mode on SATA drives

If the data protection level is set to Enhanced mode on a SATA drive, the entire capacity of a CV
must be calculated based on the previously calculated entire capacity of a CV. The calculation
methods vary depending on the unit for the capacity specified when creating the CV. These are
required to be OPEN-V.

If the CV capacity unit is MB (megabytes):

To calculate the entire capacity of a CV whose capacity unit is defined as MB:

entire-capacity-of-a-CV * 1024 / capacity-of-a-slot

where

capacity-of-a-slot

is expressed in kilobytes. The capacity of a slot depends on volume

emulation types (see

“Capacity of a slot” (page 47)

).

The resulting entire capacity is expressed in slots.

To calculate the management area capacity:

ceil(entire-capacity-of-a-CV(slots) /
calculated-management-area-capacity) * boundary-value

where

the value enclosed in ceil( ) must be rounded up to the nearest whole number.

calculated-management-area-capacity

depends on volume emulation types and

RAID levels (see

“Management area capacity of an open-systems volume” (page 46)

).

The resulting entire capacity is expressed in slots.

To calculate the entire capacity of a CV if the data protection level is set to the Enhanced mode
on the SATA drive:

ceil(entire-capacity-of-a-CV(slots) + calculated-management-area-capacity)

To convert the resulting entire capacity into megabytes:

calculated-entire-capacity-of-a-CV(slots) /
1024 * capacity-of-a-slot

where

calculated-entire-capacity-of-a-CV(slots)

means the entire capacity of a CV

if the data protection level is set to the Enhanced mode on the SATA drive.

If the CV capacity unit is block:

To calculate the entire capacity of a CV whose capacity unit is defined as block:

VLL size calculations

45

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