HP XP Racks - Manual (Page 21)

Total number of differential tables per migration plan = (X ч 256) ч Z
The variables are explained below:
•
X: The capacity of the volume to be migrated (in kilobytes). If the volume is divided by the
Virtual LVI function, this value is the capacity of the divided volume.
•
Z: The number of the slots that can be managed by a differential table.
The capacity of an OPEN-V volume is 3,019,898,880 kilobytes, and the number of slots that can
be managed by a differential table is 20,448. The formula is calculated below:
(3,019,898,880 ч 256) ч 20,448 = 576.9014085
When you round up 576.9014085 to the nearest whole number, it becomes 577. Therefore, the
total number of required differential tables for each migration plan is 577 when the emulation type
is OPEN-V.
One pair table can be used for 36 differential tables. Therefore the number of pair tables for one
migration plan is 17 when the emulation type is OPEN-V.
Differential tables calculation for other open emulation types
The following equation is used to calculate the required amount of differential tables for OPEN-3,
OPEN-8, OPEN-9, OPEN-E, and OPEN-L volumes.
Total number of the differential tables per migration plan = (X ÷ 48 + Y Ч 15) ч Z
The variables are explained below:
•
X: The capacity of the volume to be migrated (in kilobytes). If the volume is divided by the
Virtual LVI function, this value is the capacity of the divided volume. The Virtual LVI function
is not available for OPEN-L volumes.
•
Y: The number of control cylinders.
•
Z: The number of the slots that can be managed by a differential table.
If the emulation type of a volume is OPEN-3, the capacity is 2,403,360 (in kilobytes) and the
number of control cylinders is 8. Both of these figures are provided in the preceding table. The
number of slots that can be managed by a differential table is 20,448. The formula is calculated
below:
(2,403,360 ч 48 + 8 Ч 15) ч 20,448 = 2.454518779
When you round up 2.454518779 to the nearest whole number, it becomes 3. Therefore, the
total number of required differential tables for each migration plan is 3 when the emulation type
is OPEN-3.
One pair table can be used for 36 differential tables. Therefore the total number of the pair tables
for one migration plan is 1 when the emulation type is OPEN-3.
Running concurrent migration plans
To implement a migration plan, the differential tables and the pair tables are necessary as resources.
The differential tables and the pair tables are the resources shared by Auto LUN, Business Copy
and Business Copy Z. The number of differential tables and pair tables used in one storage system
differs depending on whether the dedicated shared memories are added. Concurrent migration
plans cannot be implemented at a time if the number of system volumes in the storage system is
more than half of the total number of system volumes. If you want to add the dedicated shared
memories, call the HP Support Center.
Running concurrent migration plans 21