HP StorageWorks XP Remote Web Console Software - Manual (Page 44)

* If the volume is divided by VLL function, you need to apply the capacity of the volume after the division.
You cannot perform VLL operations on an OPEN-L volume. Therefore, if the emulation type is OPEN-L, the
value substitute for (X) is the default capacity of the volume.
The following table shows the number of the control cylinders according to the emulation types.
Table 10 Number of Control Cylinders According to Emulation Types
Emulation Type Number of the Control
Cylinders
OPEN-3
8
(5,760KB)
OPEN-8, OPEN-9
27
(19,440KB)
OPEN-E
19
(13,680KB)
OPEN-L
7
(5,040KB)
OPEN-V
0
(0KB)
Conditions for the Number of Business Copy Pairs that can be Created (No LUSE Volume
Exists)
The number of Business Copy pairs that can be created will change according to whether LUSE volumes
are used or not. This section describes how to calculate the number of Business Copy pairs that can be
created when no LUSE volume is used (for example, 1 LU consists of one volume).
When you do not use LUSE volumes, you can use the following inequation to know whether you will be
able to create the desired number of Business Copy pairs or not.
You need to satisfy the inequalities below:
Σ {(α) x (the number of Business Copy pairs)} ≤(β)
and Σ {(γ) x (the number of Business Copy pairs)} ≤(δ)
• (α): The required number of differential tables per pair.
(α) changes according to the emulation type. For information about how to calculate (α), see
Table 9 on page 43.
• (β): The number of differential tables available in the storage system.
(β) will differ according to the installed additional shared memory for differential tables. For
details, see Table 8 on page 42.
• (γ): The required number of pair tables per pair.
(γ) changes according to the value of (α). For information about how to calculate (γ), see
Table 9 on page 43.
• (δ): The number of pair tables available in the storage system.
(δ) will differ according to the installed additional shared memory. For details, see
Table 8 on page 42.
For example, if you are to create 10 pairs of OPEN-3 volumes and 20 pairs of OPEN-L volumes in a
storage system that has 26,176 differential tables, you can use the condition inequation as follows:
When the emulation type is OPEN-3, and if the capacity of the volume is 2,403,360 kB, the number of
differential tables required for a pair will be 3, and the number of pair tables required for a pair will
be 1. When the emulation type is OPEN-V, and if the capacity of the volume is 3,019,898,880 kB, the
number of differential tables required for a pair will be 577, and the number of pair tables required
for a pair will be 17.
If you apply these numbers to the above-mentioned inequation:
44 Preparing for Business Copy Operations