Oracle Database ccNUMA support and dynamic partitioning on HP-UX (Doc ID 761065.1)

Last updated on JUNE 06, 2019

Applies to:

Symptoms

When running Oracle 10g or higher on an HP-UX server configured with dynamic partitions, the following errors may occur:

Changes

Recommendation

100% ILM is the default configuration for HP cell based servers. This configuration will impose no restrictions on partitioning, and will provide predictable performance in a dynamic environment.

Servers configured with 100% Interleaved Memory (ILM) should run with Oracle’s ccNUMA optimizations disabled.

Oracle support does not recommended using init.ora parameter "_enable_NUMA_optimization" to disable NUMA.  Apply the Patch 8199533 to disable NUMA.

Customers, who want to take advantage of Oracle’s ccNUMA optimizations should configure the system with both Cell Local Memory (CLM) and interleaved memory (ILM) using the command line parcreate or parmodify or Partition Manager GUI parmgr. Enough CLM should be configured to at least hold the Oracle SGA.

Requirements

When Oracle’s ccNUMA optimizations are enabled, the system or partition Oracle runs in must be configured with both Cell Local Memory (CLM) and Interleaved Memory (ILM). The amount of CLM is application dependent but there should be at least enough CLM to hold Oracle’s SGA. It may be desirable to increase the amount of CLM to allow the private data of Oracle processes to be allocated out of CLM as well.

The following rules apply, when Oracle runs with ccNUMA optimizations enabled:

Oracle Database ccNUMA support is not compatible with adding cells/CPUs or dynamic reconfiguration events activating or deactivating CPUs causing an entire cell to be removed from the system.

These operations may cause an instance to terminate if the cell was present when Oracle started and ccNUMA optimizations were enabled.

The localities (cells) present at database startup have to be always available and therefore cannot be deactivated during the lifetime of the Oracle instance. A “CPU-less” locality is not supported; there must be at least one CPU visible to Oracle in all localities at all times.

Taking a subset of CPUs offline from a cell is tolerated as long as the entire CPU set is not removed.

Once the Oracle database is started adding a new cell and removing the same cell is tolerated but not supported.

Adding and removing cells can not be done during database startup or shutdown.

Cause

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