Calculating Maximum Number Of Pairs; Organizing Volumes Into S-Vols And T-Vols - HP StorageWorks P9000 - Disk Arrays User Manual

Table 3 Control cylinders per emulation type
Emulation type
3380-3, 3380-3A, 3380-3B, 3380-3C
3390- 1
3390-2, 3390-3, 3390-3A, 3390-3B, 3390-3C, 3390-3R
3390-9, 3390-9A, 3390-9B, 3390-9C
3390-L, 3390-LA, 3390-LB, 3390-LC
3390-M, 3390-MA, 3390-MB, 3390-MC
Having determined the number of differential and pair tables required per pair on your storage
system, you can now calculate the maximum number of pairs.

Calculating maximum number of pairs

With the calculation for the number of differential and pair tables done in the previous section,
you can determine the maximum number of pairs your storage system can support.
To calculate the maximum number of pairs allowed on your system
Use the following formula:
Σ(α) ≤ (β) and Σ(γ) ≤ (δ)
where:
Σ(α) is the total number of differential tables per pair (per previous calculation).
(β) is the number of differential tables available in the system (see
Σ(γ) is the total number of pair tables per pair (per previous calculation).
(δ) is the number of pair tables available in the system
(β) and (δ) will differ according to the installed additional shared memory for differential
tables.
For example, if you are to create 10 pairs of 3390-3 volumes and 20 pairs of 3390-L volumes in
a storage system that has 26,176 differential tables, the following equation would be used to
calculate Σ(α) and Σ(γ):
Σ(α) : (3 x 10) + (24 x 20) = 510
Σ(γ) : (1 x 10) + (1 x 20) = 30
Since 510 is smaller than 26,176, and 30 is smaller than 8,192, it meets the equation, Σ(α) ≤
(β) and Σ(γ) ≤ (δ), thus insuring that 10 pairs of 3390-3 volumes and 20 pairs of 3390-L volumes
can be created.

Organizing volumes into S-VOLs and T-VOLs

Before creating pairs, it is necessary to prepare volumes for Business Copy Z. The following table
provides an example of volume information to prepare volumes.
Table 4 Volume information for Business Copy Z for z/OS
CU LDEV
0 00
0 01
etc... ...
S-VOL? Associated T-VOLs
Yes 0:10, 0:1 1
Yes 0:12, 0:13
... ...
Number of control cylinders
7
5
6
25
23
53
Table 2 (page
(Table 2 (page 12)).
T-VOL?
No
No
...
Planning pair volumes
12)).
Associated S-VOL
NA
NA
...
13