HP XP20000XP24000 Disk Array - Manual (Page 23)

Table 6 The Total Number of the Differential Tables Per Migration Plan
Emulation Type Expression
OPEN-3 Total number of the differential tables per migration plan = ((X) ÷ 48 + (Y) Ч
15) ч (Z)
(X): The capacity of the volume to be migrated. (kilobyte)*
(Y): The number of the control cylinders. (See
Table 7 on page 24)
(Z): The number of the slots that can be managed by a differential table.
(20,448)
Note that you should round up the number to the nearest whole number.
For example, if the emulation type of a volume is OPEN-3, and when provided
that the number of the cylinders of the volume is 2,403,360 kilobytes ((X) in the
expression above), the calculation of the total number of the differential tables
is as follows.
(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 the differential tables for one migration plan is 3
when emulation type is OPEN-3.
One pair table can be used for 36 differential table. Therefore the total number
of the pair tables for one migration plan is 1 when emulation type is OPEN-3.
OPEN-8
OPEN-9
OPEN-E
OPEN-L
OPEN-V
Total number of the differential tables per migration plan = ((X) ч 256) ч (Z)
(X): The capacity of the volume to be migrated. (kilobyte)*
(Z): The number of the slots that can be managed by a differential table.
(20,448)
Note that you should round up the number to the nearest whole number.
For example, if the emulation type of a volume is OPEN-V, and when provided
that the number of the cylinders of the volume is 3,019,898,880 kilobytes ((X)
in the expression above), the calculation of the total number of the differential
tables is as follows.
(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 the differential tables for one migration plan is
577 when emulation type is OPEN-V.
One pair table can be used for 36 differential table. Therefore the total number
of the pair tables for one migration plan is 17 when emulation type is OPEN-V.
The emulation type OPEN-V can only be used, if you use multiple pair tables on
the open system.
* If the volume is divided by the VLL function, this value means the capacity of the divided volume. Note
that if the emulation type is OPEN-L, the VLL function is unavailable.
The following table shows the number of the control cylinders according to the emulation types.
XP24000 Auto LUN Software User's Guide 23