LUN (VLL) and Volume Shredder User Guide (T5214-96094, November 2011)

To calculate the entire capacity of a CV, use the following formula. The resulting entire capacity

is expressed in blocks. To convert the resulting entire capacity into megabytes, divide the

capacity by 2,048.

(user-specified-CV-capacity + management-area-capacity × 2) ÷ (boundary-value × 2) ×

(boundary-value × 2)

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 blocks.

◦ The management area capacity is expressed in kilobytes. The management area capacity

depends on the volume emulation types (see Table 7 (page 15)).

◦ The boundary value is expressed in kilobytes. The boundary value depends on the volume

emulation types and RAID levels (see Table 8 (page 16)). 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 Table 9 (page 16)).

◦ The CV capacity recognized by hosts is the same as the CV capacity calculated by this

formula.

◦ If block is selected as the capacity unit in the Customized Volume window or dialog

boxes, the window or dialog boxes correctly show the calculated CV capacity. However,

if MB or Cyl (cylinders) is selected as the capacity unit in the Customized Volume window

and dialog boxes, the displayed capacity might have a margin of error because of the

unit conversion. To display the exact CV capacity, select block as the capacity unit.

Size Calculation of Volumes (Data Protection Level is Set to Enhanced Mode on SATA Drive)

If the data protection level is set to the 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.

• If the unit for CV capacity is MB (megabytes):

To calculate the entire area capacity of a CV, use the following formula. The resulting entire

capacity is expressed in slots.

entire-capacity-of-a-CV x 1024 ÷ capacity of a slot

NOTE:

◦ The capacity of a slot is expressed in kilobytes.

◦ The capacity of a slot depends on the volume emulation types (see Table 10 (page 16)).

To calculate the management area capacity, use the following formula:

entire-capacity-of-a-CV(slots) ÷ calculated-management-area-capacity x boundary-value

NOTE:

◦ The value enclosed in two upward arrows ( ) must be rounded up to the nearest whole

number.

◦ The calculated management area capacities depend on the volume emulation types and

RAID levels (see “Calculated Management Area Capacities” (page 17)).

To calculate the entire capacity of a CV if the data protection level is set to the enhanced

mode on the SATA drive, use the following formula:

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

14 About Virtual LVI/LUN and Volume Shredder