HP XP20000XP24000 Disk Array User Manual
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of differential tables and pair tables needed for migrating a mainframe volume, see
Calculating Differential Tables Required for Mainframe Volume Migration
For the number of differential tables needed for migrating an open-system volume, see
Calculating Differential Tables Required for Open-System Volume Migration
You can estimate the maximum number of migration plans that can be executed concurrently by applying
the above conditions into the following equation:
•
Σ(α) ≤ (β) and Σ(γ) ≤ (δ)
Σ(α) stands for the total number of differential tables needed for migrating all volumes
(β) stands for the number of differential tables available in the storage system.
Σ(γ) stands for the total number of pair tables needed for migrating all volumes.
(δ) stands for the number of pair tables available in the storage system.
For example, if you want 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 section
Calculating Differential Tables Required for Open-System Volume Migration
[ (3 x 20) = 60 ] ≤ 26,176 and [ (1 x 20) = 20 ] ≤ 8,192
Since this equation is true, you can create all the migration plans that you want to create.
In this section, we mentioned the calculation of the maximum number of migration plans when only Auto
LUN is running. However, in fact, the total number of differential tables used by XP Snapshot, Business
Copy, ShadowImage for Mainframe, Compatible FlashCopy, Compatible FlashCopy V2, the total number
of pair tables used by Business Copy, ShadowImage for Mainframe, Compatible FlashCopy and Auto
LUN should be within the value of (β) and (δ). For details on how to calculate the number of differential
tables and pair tables used by the programs other than Auto LUN, see the following manuals:
•
For Business Copy, see HP StorageWorks XP24000 Business Copy Software User’s Guide.
•
For ShadowImage for Mainframe, see Hitachi ShadowImage for z/OS User's Guide.
•
For Compatible FlashCopy and Compatible FlashCopy V2, see HP StorageWorks XP24000 for
Compatible FlashCopy Mirroring Software User's Guide.
•
For XP Snapshot, see HP StorageWorks XP24000 Snapshot User’s Guide.
Calculating Differential Tables Required for Mainframe Volume Migration
When you migrate mainframe volumes, use the following expression to calculate the total number of
the required differential tables and pair tables per migration plan.
Total number of the differential tables per migration plan = ((X) + (Y)) Ч 15 ч (Z)
(X): The number of the cylinders of the volume to be migrated.*
(Y): The number of the control cylinders. (See
(Z): The number of the slots that can be managed by a differential table.
(20,448)
* If the volume is divided by the VLL function, this value means the number of the cylinders of
the divided volume.
Note that you should round up the number to the nearest whole number.
For example, in case of a volume which emulation type is 3390-3, and when provided that the number of
the cylinders of the volume is 3,390 ((X) in the expression above), the calculation of the total number
of the differential table is as follows.
(3,339 + 6) Ч 15 ч (20,448) = 2.453785211
When you round up 2.453785211 to the nearest whole number, it becomes 3. Therefore, the total number
of the differential table for one migration plan is 3 when emulation type is 3390-3.
One pair table can be used for 36 differential tables. Therefore, the number of pair tables for one
migration plan is 1 when emulation type is 3390-3. Two pair tables are used if the emulation type is
3390-M and the number of volume cylinders is default number. The emulation type is 3390-M if multiple
pair tables are used on a mainframe system.
XP24000 Auto LUN Software User's Guide
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