HP XP7 Storage - Manual (Page 36)

SSID requirements
The storage system is configured with one SSID (Storage System ID) for each group of 64 or 256
devices, so there are one or four SSIDs per CU image. Each SSID must be unique to each connected
host system. SSIDs are user-specified and are assigned during storage system installation in
hexadecimal format, from 0004 to FEFF.
The following table shows the relationship between controller emulation types and SSIDs.
Virtual LVI Support SSID requirement Controller emulation type
3390-3, 3390-3A, 3390-3B, 3390-3C, 3390-9,
3390-9A, 3390-9B, 3390-9C, 3390-L, 3390-LA, 0004 to FEFF I-2107
3390-LB, 3390-LC, 3390-M, 3390-MA, 3390-MB,
3390-MC volumes
Virtual LVI size calculations
When creating a CV, you can specify the capacity of each CV. However, 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 the entire capacity from the parity group capacity. Therefore, even
if the sum of user areas of multiple CVs and the user area of one CV are the same size, the
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 the size of a 3390-A volume
To calculate the entire capacity of a CV, use the following formulas. For the
user-specified-CV-capacity
, specify the capacity of the user area in a CV.
The resulting CV capacity is expressed in megabytes:
( ceil (user-specified-CV-capacity / 1113) * 1120
* 15 * capacity-of-a-slot ) / 1024
•
The value enclosed in ceil( ) must be rounded up to the nearest whole number.
•
The user-specified-CV-capacity is the capacity of the user area in a CV expressed
in cylinders.
•
The capacity-of-a-slot is expressed in kilobytes. The capacity-of-a-slot value
depends on volume emulation types (see
“Capacity of a slot” (page 39) ).
36 Configuring custom-sized provisioning