HP StorageWorks XP Remote Web Console Software User Manual

Page 25

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How to Calculate the Number of Concurrent Migration Plans

In using XP Auto LUN for manual volume migration, the number of migration plans that can be
executed concurrently might be restricted. The number of migration plans that can be executed
concurrently depends on the following conditions:

How much shared memory is available for differential tables:

You can install additional shared memory for differential tables.

If additional shared memory for differential tables is installed, you may use 26,176, 57,600,
or 104,768 differential tables. If an XP24000 disk array is being used, you may also use
146,688, or 209,600 differential tables.

To install additional shared memory for differential tables, call HP technical support.

How much shared memory is available for pair tables:

You can install additional shared memory for differential tables.

You may use 8,192 or 16,384 pair tables if additional shared memory for pair tables is
installed.

To install additional shared memory for pair tables, call HP technical support.

The emulation type and capacity of each volume to be migrated:

The number of differential tables and pair tables needed to migrate one volume differs
depending on the emulation type and size of the volume. For the number of differential tables
and pair tables needed for migrating a mainframe volume, see

“Calculating Differential Tables

Required for Mainframe Volume Migration” (page 26)

. For the number of differential tables

needed for migrating an open-system volume, see

“Calculating Differential Tables Required

for Open-System Volume Migration” (page 27)

.

You can estimate the maximum number of migration plans that can be executed concurrently by
applying these conditions to the following equation:

( )

( ) and ( )

( )

( ) stands for the total number of differential tables needed for migrating all volumes

( ) stands for the number of differential tables available in the storage system.

( ) stands for the total number of pair tables needed for migrating all volumes.

( ) stands for the number of pair tables available in the storage system.

For example, to create 20 migration plans of OPEN-3 volumes (size of a volume is 2,403,360
kilobytes), the number of required differential tables is 3, and the number of pair tables is 1,
as calculated by the equation in

“Calculating Differential Tables Required for Open-System

Volume Migration” (page 27)

.

[ (3 x 20) = 60 ]

26,176 and [ (1 x 20) = 20 ]

8,192

Since this equation is true, you can create as many migration plans as you want.

This section discussed the calculation of the maximum number of migration plans when only XP
Auto LUN is running. However, the total number of differential tables used by XP Snapshot, XP
Business Copy, ShadowImage for Mainframe, FlashCopy Mirroring, and FlashCopy Mirroring V2,
and the total number of pair tables used by XP Business Copy, ShadowImage for Mainframe,
FlashCopy Mirroring, and XP Auto LUN should be within the value of ( ) and ( ). For details on

Interoperability with Other Products

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