Requirements, cautions, and restrictions for Virtual Partition Manager

License keys

The Virtual Partition Manager license key must be installed on the storage system.

For details about installing license keys, see the System Administrator Guide.

Access privileges

Administrator access or write access is required to perform Virtual Partition Manager operations. Users without Administrator access or write access can only view the performance management information and settings. You need specific administrator roles to use the following functions:

• Performance Monitor: Storage Administrator (Performance Management)
• Server Priority Manager, Virtual Partition Manager: Storage Administrator (System Resource Management)
• Quality of Service: Storage Administrator (System Resource Management)

Cache memory

Use of Virtual Partition Manager might require additional cache memory in your storage system.

Increased cache memory requirements

Install additional cache memory before partitioning cache. Adding cache memory after CLPRs have been created is difficult and can be problematic. For details, see Cache partitioning workflow.

Impact on host performance

Creating and changing cache logical partitions can significantly degrade host performance and should only be performed during the initial installation and setup of the storage system or during maintenance. If you must perform these changes on a production machine, use Performance Monitor to verify that the write pending rate and sidefile occupancy rate of the CLPR and CLPR0 satisfy the following formulas on all MP units:

For a CLPR with decreased cache capacity:

Write pending rate x cache capacity before operation / 
cache capacity after operation < 30%

Sidefile occupancy rate x cache capacity before operation / 
cache capacity after operation < sleep wait threshold x 50%

For a CLPR with increased cache capacity:

Sidefile occupancy rate < sleep wait threshold x 50%

Moving resources in CLPRs

When you move resources in CLPRs, make sure that the writing pending rate of the MP units for each CLPR is less than 50% at both the source and the destination. The process for changing the CLPR settings will be suspended until the write pending rates of each MP unit become less than 50%.

When you perform the following CLPR operations successively, you must wait for the current CLPR operation to complete before starting the next one. If the next CLPR operation is performed before the completion of the current CLPR operation, the last operation is enabled. Verify the CLPR settings, and then retry the operation:

• Creating a CLPR
• Deleting a CLPR
• Moving resources within a CLPR
• Editing CLPR settings

As an exception, you can move resources in a CLPR while resources are being moved in another CLPR.

Duration of cache partition operations

Adding or changing CLPR definitions or configurations can take hours to complete. After a CLPR operation has been started, you cannot cancel or modify the process until the operation is complete.

ShadowImage, ShadowImage for Mainframe

You cannot use ShadowImage or ShadowImage for Mainframe Quick Restore functions that affect multiple CLPRs.

Volume Migration

You cannot use Volume Migration when it affects multiple CLPRs.

Universal Replicator

Universal Replicator data volumes and journal volumes can belong to different CLPRs. All journal volumes in the same journal must belong to the same CLPR. If not, an error occurs.