HP XP Racks - Manual (Page 16)

• Run the following RAID Manager or BCM command:
inqraid
For more information about running this command, see the HP XP7 RAID Manager User Guide
and the Business Continuity Manager User Guide.
Calculating the number of tables for Business Copy Z
You can calculate the number of differential and pair tables your XP7 storage system needs to
create BC Z pairs.
NOTE: This calculation assumes that you are only using BC Z in the system.
1. Use the following function:
Total number of the differential tables per pair = ((the number of
cylinders in a volume) + (number of the control cylinders*) Ч 15 ч
(20,448**)
* See the table that shows control cylinders per emulation type in this section.
** Number of the slots that a differential table can manage.
2. Round up the total number to the nearest whole number.
For example, if the emulation type is 3390-3 and if the number of the cylinders of the volume is
3339, use the following calculation to get the total number of the differential tables:
((3,339 +6) x 15) ÷ 20,448 = 2.4537
Round up 2.4537 to the nearest whole number, 3. In this example, you will need three differential
tables and one pair table.
The following table shows control cylinders per emulation type.
Number of Control Cylinders Emulation Type
6 3390-3, 3390-3A, 3390-3B, 3390-3C
25 3390-9, 3390-9A, 3390-9B, 3390-9C
23 3390-L, 3390-LA, 3390-LB, 3390-LC
53 3390-A, 3390-M, 3390-MA, 3390-MB, 3390-MC
If the volume is divided by VLL, use the volume capacity after the division.
Calculating the maximum number of BC Z pairs
You can calculate the maximum number of BC Z pairs your XP7 storage system can support. In
the calculation, you use the results of calculating the number of differential and pair table.
16 Business Copy Z system requirements and planning