HP XP P9500 Storage - Manual (Page 13)

Requirement Item
Maximum number of pairs decreases if LUSE volumes are used.
Consistency groups • You can configure up to 256 consistency groups in a storage system, including BC,
BC Z, and Snapshot consistency groups.
Note: BC, BC Z, and Snapshot pairs cannot co-exist in the same consistency group.
•
You can define up to 8,192 Business Copy pairs in a consistency group.
Note: LUSE volumes that contain n LDEVs should be counted as n volumes. See HP XP
P9000 Provisioning for Open Systems User Guide for more information.
• A number (0–FF) is assigned to each consistency group. You specify a consistency
group number when you create pairs. If you do not specify a number, the storage
system automatically assigns it.
- Consistency group numbers 00 to 7F (or 0 to 127) can be used commonly for Business
Copy, Business Copy Z, and Snapshot. Consistency group numbers 80 to FF (or 128
to 255) are exclusively used for Snapshot.
License capacity requirements
The total capacity of 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.
•
Primary volumes, secondary volumes, and volumes are reserved for use as secondary volumes
must have licensed capacity.
•
Snapshot primary volumes and pool volumes require the Business Copy license 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.
•
When a Thin Provisioning volume is used as a Business Copy primary or secondary volume
(or as a reserved volume), the capacity of the Thin Provisioning pool allocated to the volume
is added to the Business Copy license capacity. The reason is because Thin Provisioning
volumes are not updated in real time. As a result, some write requests may cause excess data,
which is saved in the pool.
When your Business Copy volumes exceed license capacity, you are allowed to use the volumes
for additional 30 days. After that, Business Copy operations can no longer be performed, except
to delete pairs. For more information, see the HP XP P9000 Remote Web Console User Guide.
Planning pair volumes
You must create volumes for primary volumes and secondary volumes prior to creating pairs.
Review system requirements for pair volumes in
(page 12) . Also, the following options can be
used:
•
Before creating a pair, you can reserve a volume as an secondary volume. This insures that
no I/O occurs in the reserved volume before creating the pair. Reserved volumes may only
be used as secondary volumes.
•
If you use , you can place a group of pairs in a consistency group. Using the consistency
group, you can perform pair operations on all the pairs in the group at the same time, including
consistency-group pair-split operations. See the HP XP P9000 RAID Manager User Guide for
information on setting up consistency groups and performing pair operations.
License capacity requirements 13