Cv capacity by emulation type for open systems, Vll size calculations – HP XP P9500 Storage User Manual

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Open system

Parameter

65,280

Maximum number of volumes (normal and
Virtual LUN) per storage system

See

“CV capacity by emulation type for open systems” (page 45)

Maximum size for one Virtual LUN volume

1 MB

Size increment

Anywhere

Disk location for Virtual LUN volumes

CV capacity by emulation type for open systems

Number of control cylinders
(cyl)

Maximum CV capacity

Minimum CV capacity (CYL)

Emulation type*

0 KB (0 cyl)

3,221,159,680 KB (2.99
TB)

48,000 KB

OPEN-V

5,760 KB (8 cyl)

2,403,360 KB

36,000 KB (50 cyl)

OPEN-3

19,440 KB (27 cyl)

7,175,520 KB

36,000 KB (50 cyl)

OPEN-8

19,440 KB (27 cyl)

7,211,520 KB

36,000 KB (50 cyl)

OPEN-9

13,680 KB (19 cyl)

14,226,480 KB

36,000 KB (50 cyl)

OPEN-E

*Virtual LUN operations are not available for OPEN-L volumes.

VLL size calculations

When creating a CV, you can specify the capacity of each CV. However, a rounding will produce
different values for the user-specified CV capacity and the actual entire CV capacity. To estimate
the actual capacity of a CV, use a mathematical formula. The following topics explain how to
calculate the user area capacity and the entire capacity of a CV.

The capacity of a CV or an LDEV consists of two types of capacity. One type is the user area
capacity that stores the user data. The second type is the capacities of all areas that are necessary
for an LDEV implementation including control information. The sum of these two types of capacities
is called the entire capacity.

Implemented LDEVs consume this entire capacity from the parity group 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 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

VLL size calculations

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