Managing memory properties for shared memory partitions

You can use the Integrated Virtualization Manager to manage memory attributes for logical partitions that use shared memory.

For logical partitions that use shared memory, you can use the Integrated Virtualization Manager to manage some additional memory properties that apply to these partitions.

You can change the memory weight for the shared memory partition. The memory weight is a relative value that is one of the factors that the hypervisor uses in determining the allocation of physical system memory from the shared memory pool to a shared memory partition. A higher value relative to the values set for other shared memory partitions increases the probability of the hypervisor allocating more physical system memory from the memory pool to the shared memory partition with the higher value.

A Linux® shared memory partition supports changing the memory weight only if the DynamicRM tool package is installed on the Linux shared memory partition. To download the DynamicRM tool package, see the Service and productivity tools for Linux on POWER® systems Web site.

You also can change the memory mode for the partition from shared memory mode to dedicated memory mode or from dedicated mode to shared mode. To be able to change the memory mode from shared to dedicated for a logical partition, you must have enough physical system memory available to fulfill the current Assigned memory value and the partition must be shut down.

To be able to change the memory mode from dedicated to shared for a client logical partition, the partition must use shared processors and cannot have any I/O devices or Integrated Virtual Ethernet (IVE) adapters (also known as Host Ethernet Adapters) assigned to it. The partition must be virtual. The logical partition also must be shut down.

Note: You cannot use the Integrated Virtualization Manager to change the I/O entitled memory, which is the amount of memory from the shared memory pool that the partition is entitled to use for I/O mapping purposes. The Integrated Virtualization Manager manages this property for a partition that is based on the virtual I/O configuration of the partition unless you use the IVM command line interface (CLI) to define this property.

To change the memory weight or the memory mode for a shared memory partition, complete these steps in the Integrated Virtualization Manager:

In the navigation area, select View/Modify Partitions under Partition Management. The View/Modify Partitions page is displayed.
Select the logical partition for which you want to change the memory settings.
From the Tasks menu, click Properties. The Partition Properties page is displayed.
Select the Memory tab.
Select the appropriate memory mode for the partition.
Specify a new value for the memory weight attribute in the Pending column for the attribute. The pending memory weight value must be greater than, or equal to, 0 but less than, or equal to, 255. Set this value relative to other shared memory partitions to rank the importance of having more physical memory from the shared memory pool available for this partition.
Click OK. The management partition synchronizes the current assigned value with the pending assigned value. Synchronization can take several seconds to complete. You can perform other tasks on the system while the management partition is synchronizing the current and pending values.