HP StorageWorks XP Remote Web Console Software User Manual
Page 64
Calculating the Maximum Number of Version 2 Relationships
Version 2 can establish up to 1,048,575 relationships. However, Version 2 may not be able to
establish up to 1,048,575 relationships depending on the number of resources required for the
copy operation, which varies according to the attributes (emulation type, capacity size of the data
that is copied, position of the extent) of the volumes, and extents used for establishing the
relationships.
You can use the Compatible FlashCopy Information dialog box (see
) to check the number
of remaining resources that are currently available. Check the Compatible FlashCopy Information
dialog box when you create a Version 2 relationship.
The following software programs share the resources used for copy operations:
•
ShadowImage for Mainframe
•
XP Business Copy
•
XP Snapshot
•
XP Auto LUN
The resources used by ShadowImage for Mainframe, XP Business Copy, XP Snapshot, and XP Auto
LUN cannot be used for Version 2. The remaining resources are available for Version 2. See the
following manuals for details about calculating the resources used by each software program.
•
Hitachi ShadowImage™ for Mainframe User Guide: HP XP24000 Disk Array,
HP XP20000 Disk Array
•
HP XP24000/XP20000 Business Copy Software User Guide
•
HP XP24000/XP20000 Snapshot User Guide
•
HP XP24000/XP20000 Auto LUN Software User Guide
•
Establishing relationships by volume copying
Use the following expression to calculate the total number of resources to be used per
relationship:
Total number of the differential tables per relationship = ((X) + (Y)) x 15
(Z)
◦
(X): The number of cylinders in the volume.
◦
(Y): The number of control cylinders (see
).
◦
(Z): The number of slots that can be managed by a differential table.
(639 × 32)
Round up the number to the nearest whole number.
lists the number of control cylinders for each emulation type.
Table 39 Number of Control Cylinders for Each Emulation Type
Number of Control Cylinders
Emulation Type
7
3380-3
6
3390-3
25
3390-9
23
3390-L
53
3390-M
The number of resources to be used per relationship is the total number of the resources of
the copy source and copy target. For example, in the case of a volume with emulation type
3390-3, if the number of cylinders of the divided volume is 3,390 ((X) in the expression that
64
Preparing for Version 2 Operations