Hitachi ShadowImage for z/OS user guide (HIT9503-96004, June 2006)

ShadowImage for z/OS user guide 103
Round up the number to the nearest whole number. For example, in case of a volume for which the
emulation type is 3390-3 and the number of cylinders of the divided volume is 3,390 (x in the
preceding expression), the calculation of the total number of the differential table is as follows:
(3,390 + 6) x 15 ÷ (1,916 x 32) = 0.81836
When you round up 0.81836 to the nearest whole number, it becomes 1. Therefore, the total number
of the differential table for one pair is 1 when emulation type is 3390-3.
For the information about the number of pairs that can be created, see Table 47.
When volumes that differ in the emulation type and capacity are, the number of relations that can be
established is determined according to the following condition.
The maximum number of relations that can be established is the largest number that meets the
equation, Σ(α) = (β), where:
Σ(α) stands for the total number of resources used per a pair (see Table 47), and
(β) stands for the total number of resources available in the local disk array.
(β) = 13,652 when additional shared memory is not installed.
(β) = 30,718 when additional shared memory is installed.
The figures in Table 47 represent the case when FlashCopy Mirror Version 2 alone uses all the
resources. CYL means the number of cylinder.
Table 47 Number of Relations That Can Be Established With Volumes of Each Emulation Type and
Capacity
Emulation
Type
RAID Level Number of resources used per
pair (α)
RAID1 (2D+2D) RAID5 (3D+1P) RAID5 (7D+1P) S-VOL T-VOL Total
3390-3 Does not depend on the capacity 1 1 2
3390-3R Does not depend on the capacity 1 1 2
3390-2 Does not depend on the capacity 1 1 2
3390-1 Does not depend on the capacity 1 1 2
3390-9 1 - 4,063 CYL 1 - 4,061 CYL 1 - 4,059 CYL 1 1 2
4,064 - 8,150 CYL 4,062 - 8,149 CYL 4,060 - 8,147 CYL 2 2 4
8,151 - 10,017
CYL
8,150 - 10,017
CYL
8,148 - 10,017
CYL
336
3390-L 1 - 4,064 CYL 1 - 4,063 CYL 1 - 4,061 CYL 1 1 2
4,065 - 8,151 CYL 4,062 - 8,149 CYL 2 2 4
8,152 - 12,239 CYL 8,150~ - 12,237
CYL
336
12,240 - 16,326
CYL
12,240 - 16,325
CYL
12,238 - 16,325
CYL
448
16,327 - 20,414
CYL
16,326 - 20,413 CYL 5 5 10
20,415 - 24,501
CYL
20,414 - 24,501 CYL 6 6 12
24,502 - 28,589
CYL
24,502 - 28,588
CYL
24,502 - 28,589
CYL
7714
24,590 - 32,676
CYL
24,589 - 32,676
CYL
24,590 - 32,673
CYL
8816
32,677 - 32,760
CYL
32,677 - 32,760
CYL
32,674 - 32,760
CYL
9918