HP XP P9500 Storage - Manual (Page 19)

3 Auto LUN planning
This chapter provides information about Auto LUN planning.
Manual migration plans
To migrate volumes manually, you must create migration plans. A migration plan is required for
each volume that you want to migrate, and each plan includes a source volume and target volume.
Up to eight migration plans can be applied each time you click Apply in the Manual Plan window.
If you want more than eight migration plans, you must click Apply multiple times. The number of
migration plans that can be executed concurrently might be restricted based on emulation types
and sizes of the migrated volumes, and on the resources being used by other programs.
Be careful not to perform manual migration operations while the Auto Migration function is enabled.
If you do perform manual migration plans while the Auto Migration function is enabled, all auto
migration plans in progress will be canceled. A manual migration operation is not allowed when
the current write pending rate for the storage system is 60 percent or higher.
Estimating differential tables
Differential tables are resources shared by Auto LUN, Snapshot, Business Copy, Business Copy Z,
and Compatible FlashCopy. Because an Auto LUN source volume still accepts I/O write operation
during an Auto LUN operation, differential tables are used to track and copy the differential data
to the target volume, which ultimately becomes the migrated volume. The subsequent sections
provide formulas for estimating the amount of differential and pair tables that you will need per
migration plan.
Calculating the required amount of differential tables for a mainframe
volume
When you migrate mainframe volumes, you must determine the total number of required differential
tables and pair tables per migration plan. Use the following equation to calculate the required
amount of differential tables. Figures are rounded up to the nearest whole number.
Total number of the differential tables per migration plan = (X + Y) Ч 15 ч Z
The variables are explained below:
•
X: The number of volume cylinders to be migrated. If the volume is divided by the Virtual LVI
function, this value is the number of cylinders in the divided volume.
•
Y: The number of control cylinders.
•
Z: The number of slots that can be managed by a differential table.
Control cylinders by mainframe emulation type
Before you can calculate the required amount of differential tables per migration plan, you must
know the number of control cylinders contained by the mainframe volume. The following table
shows the number of control cylinders based on the emulation type.
Table 10 Number of Control Cylinders Based on Emulation Type
Number of Control Cylinders Emulation Type
7 3380-3, 3380-3A, 3380-3B, 3380-3C
22 3380-F
7 3380-K, 3380-KA, 3380-KB, 3380-KC
6 3390-3, 3390-3A, 3390-3B, 3390-3C, 3390-3R
Manual migration plans 19