License Capacity Requirements; Planning Pair Volumes; Planning Number Of Pairs - HP StorageWorks P9000 - Disk Arrays User Manual

Table 1 System requirements (continued)
Item
Maximum Number of Pairs
Consistency groups

License capacity requirements

The total capacity of your pair volumes must be less than the maximum volume capacity licensed
to you.
After operations begin, you should be aware of capacity requirements in order to keep volumes'
total size within purchased capacity.
S-VOLs, T-VOLs, and volumes that have been reserved for use as T-VOLs must have licensed
capacity. The total of these volumes capacity must not be more than licensed capacity.
The capacity of a volume used for multiple purposes is counted only once; there is no need
to multiply the capacity by the number of purposes it is used for.

Planning pair volumes

You must create volumes for S-VOLs and T-VOLs prior to creating pairs. Review system requirements
for pair volumes in
Before you create a pair, you can reserve a volume as a T-VOL. This insures that no I/O occurs
in the reserved volume before creating a pair. Reserved volumes may only be used as T-VOLs.
(With TSO or ICKDSF commands, T-VOLs are required to be offline to the host; therefore, they
do not need to be reserved.)
If you use Business Continuity Manager, you can place a group of pairs in a copy group.
Using the copy group, you can perform pair operations on all the pairs in the group at the
same time, including the At-Time Split operation with which you can specify the split time. See
the HP StorageWorks P9000 for Business Continuity Manager User Guide for information on
setting up consistency groups and performing pair operations.
If you use PPRC, you can split the pairs in a consistency group, though the At-Time Split feature
is not available.

Planning number of pairs

This section provides instructions for calculating the number of system resources required for one
Business Copy Z pair. With this information you can calculate the maximum number of pairs.
When you create pairs, differential tables (tables managing differential bitmaps) and pair tables
are required. These must be available in sufficient number to handle all the pairs you will create.
Requirement
Maximum number possible per storage system is 16,384 pairs (when one T-VOL per
S-VOL). Actual number is based on amount of additional shared memory. See
number of pairs" (page 11)
You can configure up to 128 consistency groups in a storage system, including Business
Copy Z consistency groups and Snapshot consistency groups.
Note: Business Copy pairs and Snapshot pairs cannot coexist in the same consistency
group.
You can define up to 8,192 Business Copy Z pairs in a consistency group.
Note: LUSE volumes that contain n LDEVs should be counted as n volumes. For further
information on LUSE volumes, see HP StorageWorks P9000 Provisioning for Open
Systems User Guide.
A number (0–7F) is assigned to each consistency group. You can specify a consistency
group number when you create Business Copy Z pairs, or if you do not specify a
number, the storage system assigns a number automatically.
Table 1 (page 10). Also, the following options can be used:
for further information.
License capacity requirements
"Planning
1 1