HP XP Business Copy Software - Manual (Page 14)

Requirement Parameter
Under certain conditions, BC volume pairs may need to be re-established.
Maintenance/up-
grade
1
Maximum number of pairs per disk array depends on installed firmware version.
Maximum number of pairs for the array
When you create BC pairs, resources called differential tables are required. The number of differential
tables available in one disk array depends on the array's amount of shared memory for differential
tables.
• You can use 13,652 differential tables if no additional shared memory for differential tables is
installed.
• You can use 30,718 differential tables if additional shared memory for differential tables is installed.
NOTE:
Contact your HP account support representative for more information about adding additional
shared memory.
NOTE:
The maximum number of pairs you can create is 8,192, no matter how much shared memory for
differential tables is available. If a command device is installed in order to use RAID Manager,
the maximum number of pairs is 8,191 (when configuring pairs of 1 P-VOL: 1 S-VOL ratio).
To calculate the maximum number of BC pairs, you must calculate how many differential tables are
required to create BC pairs, and compare the result with the number of differential tables in the disk
array.
The following applications also use differential tables:
• ShadowImage for z/OS
• Hitachi FlashCopy Mirroring
• Hitachi FlashCopy Mirroring version 2
• Flex Copy XP
• Auto LUN XP
• Snapshot XP
For more information, see the following documents:
• For ShadowImage for z/OS, Hitachi FlashCopy Mirroring, and Hitachi FlashCopy Mirroring
Version 2, see the Hitachi ShadowImage for z/OS user guide.
• For Flex Copy XP, see “Calculating the maximum number of Flex Copy XP copy pairs.”
• For Auto LUN XP, see “Calculating the number of Auto LUN XP concurrent migration plans.”
• For Snapshot XP, see the HP StorageWorks Snapshot XP user guide.
If BC is used in the same disk array as any of these applications, the number of available differential
tables for BC pairs is the number of differential tables in the disk array minus the number of differential
tables used by other applications.
Business Copy XP (BC) for the Array 14