Hitachi ShadowImage for z/OS user guide (December 2005)

ShadowImage for z/OS user guide 97
Table 46 shows the compatibility between the FlashCopy Mirror Version 2 functions and the user interface
functions.
Maximum Number of FlashCopy Mirror Version 2 Pairs
FlashCopy Mirror Version 2 can establish up to 32,768 pairs. However, FlashCopy Mirror Version 2 may
not be able to establish up to 32,768 relations depending on the number of resources required for the copy
operation that vary according to the attributes (emulation type, capacity, the size of the data that is copied,
the position of the extent) of the volumes and extents used for establishing the pairs. Furthermore, the total
number of available resources also varies according to the number of CUs. You can use the FlashCopy
Information pane (see Figure 22) to check the number of remaining resources that are currently available.
Check the FlashCopy Information pane when you create a FlashCopy Mirror Version 2 pair.
NOTE: The following software programs share the resources used for copy operation.
• ShadowImage for z/OS
• Business Copy XP
• Auto LUN XP
• Flex Copy XP
• Snapshot XP
The resources used by ShadowImage for z/OS, Business Copy XP, Auto LUN XP, Flex Copy XP, and
Snapshot XP cannot be used for FlashCopy Mirror Version 2. The resources that remain when you exclude
the resources used by ShadowImage for z/OS, Business Copy XP, Auto LUN XP, Snapshot XP, and Flex
Copy XP from the total resources are available resources for FlashCopy Mirror Version 2. For details about
the calculation of the resources used by each software program, refer to the following manuals.
• HP StorageWorks Business Copy XP User Guide for the specific disk array
• HP StorageWorks Auto LUN XP User Guide for the specific disk array
• HP StorageWorks Flex Copy XP User Guide
• HP StorageWorks Snapshot XP User Guide
For details about ShadowImage for Mainframe, see
”Requirements on the Maximum Number of Pairs” on
page 16
.
• Creating pairs by volume copying
Use the following expression to calculate the total number of the differential tables per pair:
Total number of the differential tables per pair = ( (X) + (Y) ) x 15 ÷ (Z)
(X): Number of the cylinders of the volume that is divided at arbitrary size.
(Y): Number of the control cylinders (see Table 3).
(Z): Number of slots that can be managed by a differential table.
(1,916 x 32)
Table 46 Compatibility between FlashCopy Mirror Version 2 and User Interface Functions
User Interface Function Functions
Volume
copying
Dataset
copying
COPY mode NO COPY
mode
DFSMSdss TSO Multiple relations Supported Supported Supported Supported
COPY mode Supported Supported Supported
1
1. Represents the case when the copy operation mode is changed from NOCOPY mode to COPY mode.
N/A
NOCOPY mode Supported Supported N/A N/A