HP XP P9000 Business Copy User Guide (AV400-96573, July 2013)
Table Of Contents
- HP XP P9000 Business Copy User Guide
- Contents
- 1 Business Copy overview
- 2 Requirements and planning
- 3 Sharing Business Copy volumes
- Cache Residency
- Fast Snap and Snapshot
- Data Retention
- Thin Provisioning and Smart Tiers
- External Storage Access Manager
- LUN Manager
- Open Volume Management
- Resource Partition
- Continuous Access Synchronous
- Continuous Access Journal
- External Storage
- Auto LUN
- 4 Performing configuration operations
- 5 Performing pair operations
- 6 Monitoring and maintaining the system
- 7 Troubleshooting
- 8 Support and other resources
- A Interface support for BC operations and options
- B Business Copy GUI reference
- Replications window
- Local Replications window
- View Pair Properties window
- View Pair Synchronous Rate window
- View Histories window
- Consistency Group Properties window
- Create Pairs wizard
- Split Pairs wizard
- Resync Pairs wizard
- Suspend Pairs window
- Delete Pairs window
- Edit Mirror Units dialog box
- Change Options dialog box
- Add Reserve Volumes Wizard
- Remove Reserve Volumes window
- Edit Local Replica Option wizard
- C Configuration operations (secondary window)
- D Pair operations (secondary window)
- E Monitoring and maintaining the system (secondary window)
- F Business Copy GUI reference (secondary window)
- Glossary
- Index
Differential tables (tables managing differential bitmaps) and pair tables are required to create
pairs. You must supply an adequate number of tables to handle all the pairs you plan to create.
The number of differential and pair tables that are present in the system depends on additional
shared memory that is installed. Therefore, you must ensure that you have sufficient additional
shared memory to handle the number of pairs.
The following table shows the number of differential and pair tables and the number of volumes
allowed per additional shared memory. The maximum number of pairs is half the number of volumes
shown, when P-VOLs and S-VOLs are in a one-to-one relationship.
For example, if additional shared memory is not installed, since the number of volumes is 16,384,
then the number of pairs you can create is 8,192. This example assumes one S-VOL per P-VOL. If
there are more S-VOLs than P-VOLs, then the number of allowed pairs decreases.
However, for Extension 1 and Extension 2, the maximum number of pairs is 16,384, regardless
of the total number of system volumes.
Table 1 Differential tables, pair tables, additional shared memory
Number of system
volumes
Number of pair tablesNumber of diff. tablesAdditional shared memory
16,3848,19226,176Base (No additional shared memory)
65,53616,384104,768Extension 1
65,53616,384209,600Extension 2
You can determine the maximum number of pairs that can be created on your system by calculating
the number of differential and pair tables your system needs to create BC pairs. This number must
be equal to or less than the difference of the total number of differential and pair tables in the
storage system, minus the number of tables being used by the other products (for example,
Compatible FlashCopy).
The following software products also use differential tables:
• BC Z
• Compatible FlashCopy
• Compatible FlashCopy SE
• Auto LUN
• SS
The following software products also use pair tables:
• BC Z
• Auto LUN (using migration plans)
NOTE: You can use RAID Manager’s inqraid command to query the number of the differential
tables required when you create BC pairs, though not for creating BC Z pairs. For BC, you can
also query the number of differential tables not used in the storage system with this command.
For more information about the inqraid command, see the HP XP P9000 RAID Manager User
Guide.
Calculating the number of differential tables and pair tables
Calculations in the following sections assume that you are only using BC in the system.
The emulation type of your volumes affects the number of differential and pair tables.
14 Requirements and planning