HP XP Racks - Manual (Page 15)

Software applications that use tables
The following XP7 software applications use differential tables:
•
Business Copy
•
Auto LUN
The following XP7 software applications use pair tables:
•
Business Copy
•
Auto LUN (using migration plans)
Tables and installed shared memory
The number of differential and pair tables that are present in the XP7 storage system depends on
the amount of installed shared memory. Ensure that you have sufficient shared memory to handle
the number of BC Z pairs you plan to create.
The following table shows the maximum amounts of differential and pair tables and system volumes
you can create based on the amount of installed shared memory.
System volume limit Pair table limit Differential table limit Shared memory
16,384 8,192 57,600 Base (No additional shared memory)
65,536 32,768 419,200 Extension 1
The maximum number of BC Z pairs you can create is half the number of system volumes shown
in the table if the P-VOLs and S-VOLs are in a one-to-one relationship.
For example, if you have only the base shared memory installed and the maximum amount of
system volumes you can create is 16,384, then you can only create 8,192 BC Z pairs. If there
are more S-VOLs than P-VOLs, then the number of allowed BC Z pairs decreases.
Installing Extension 1 does not increase the amount of BC Z pair tables you can create. The system
volume amount does not affect the pair table limit.
Calculating the number of tables if you are sharing tables
You can calculate the number of differential and pair tables your XP7 storage system needs to
create BC Z pairs.
•
Use the following formula:
The number of differential and pair tables your XP7 storage system
needs =< (the total number of differential and pair tables in the
XP7 storage system - the number of tables other software applications
are using, such as Compatible FlashCopy)
Determining the number of tables required for Business Copy Z
You can query the number of differential tables that are required to create Business Copy (BC/SS)
pairs.
•
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.
Determining the number of used tables in the storage system
You can query the number of differential tables that are not used in the XP7 storage system.
Determining capacity of BC Z pairs in XP7 workflow 15