HP XP P9000 Continuous Access Synchronous for Mainframe Systems User Guide

• When creating a pair with RAID Manager, Auto is automatically used. No other option is
available.
• If VLL is used, the number of cylinders that you set with VLL software is used to determine the
Auto setting.
◦ If the P-VOL has 10,019 or more cylinders, Cylinder is set.
◦ If the volume has less than 10,019 cylinders, Track is set.
Maximum number of pairs supported
Cnt Ac-S Z supports a maximum of 32,768 pairs, which is the maximum number of pairs supported
by the XP P9500 storage system. If BCM or RAID Manager is used, a command device must be
defined for each product; therefore, the maximum number of pairs in XP P9500 is calculated by
subtracting the number of command devices from 32,768.
Calculating maximum number of pairs
It is necessary to calculate the maximum number of pairs you can have on the XP P9500 storage
system. The maximum number is based on the following:
• The number of cylinders in the volumes, which must be calculated.
• The number of bitmap areas required for a Cnt Ac-S Z volume, which is calculated using the
number of cylinders.
NOTE: In the following formulas, ceil() indicates that the result within the parentheses should
be rounded up to the nearest integer, and floor() indicates that it should be rounded down to
the nearest integer.
Procedure 1 To calculate the maximum number of pairs
1. Calculate the number of cylinders using one of the following formulas:
• For pairs created with a Virtual LVI volume or THP V-VOL:
When the emulation type is 3380
Number of cylinders = (ceil ( (ceil (Number of logical blocks/
96) ) / 15) )
When the emulation type is 3390
Number of cylinders = (ceil ( (ceil (Number of logical blocks /
116) ) / 15) )
• For pairs created without a Virtual LVI volume or THP V-VOL, find the number of cylinders
for your system’s emulation type in the following table.
Number of cylindersEmulation type
1,1133390-1
2,2263390-2
3,3393390-3, 3390-3R
10,0173390-9
262,6683390-A
32,7603390-L
65,5203390-M
Planning pairs and pair volumes 37