i5/OS: Dynamically moving memory

Dynamically moving memory

Memory in each logical partition operates within its assigned minimum and maximum values. You can dynamically move memory between logical partitions without needing to restart the affected partitions as long as your request for memory movement is within the range of the minimum and maximum values specified during partition creation.
When you request to dynamically move memory between partitions, you should note that this memory is removed and added to the base memory pool of each of the partitions (*BASE pool). Private memory pools or shared memory pools are not affected. If the move request exceeds the amount of memory available in the base pool, the system will only free up excess memory pages after keeping the minimum amount of memory required in the base pool. This value is determined by the base storage minimum size (QBASPOOL) system value. To prevent any data loss during memory movement, the system first writes any data from memory pages to the disks before making the memory pages available to another partition. Depending on the amount of memory you have requested to move, this may take some time.
Each partition will report its runtime minimum memory size. This value is an estimate of how much memory in the partition is locked into that partition and cannot be moved dynamically. Reducing the number of processes or threads within a partition or changing the *BASE pool will affect the runtime minimum.
The full amount of memory that you assign to a logical partition may not be available for the partition's use. Static memory overhead required to support the assigned maximum memory will affect the reserved or hidden memory amount. This static memory overhead will also influence the minimum memory size of a partition.
The minimum memory size assigned to a partition can be changed with only a restart of the partition. However, changes to the maximum memory size require a restart of the entire system and may require a larger minimum memory value.
To move memory from one logical partition to another using My Connections, follow these steps:

In iSeries™ Navigator, expand My Connections or your active environment.
Select the primary partition of the system.
Expand Configuration and Service and select Logical Partitions.
Right-click the Logical Partition and select Configure Partitions. You are now working in the Configure Logical Partitions window.
Select the partition from which you would like to move memory.
Right-click Memory and select Move.
Specify the amount of memory to move in Memory to move. This value must be less than the current amount of memory available to the logical partition. The Memory after Move values for both the source and receiving partitions must fall within the minimum/maximum ranges specified for memory.
Select the partition to receive the memory in To logical partition.
Click OK to move the memory you specified.

To move memory from one logical partition to another using the service tools window, follow these steps:

In iSeries Navigator, select My Connections or your active environment.
Select Open iSeries Navigator service tools window in the Taskpad window. If the Taskpad window is not displayed, select View and select Taskpad.
Enter the IP address of the service tool network interface to which you want to connect. Click OK.
You will be prompted for your Service Tools User ID and password.
Expand the system name select Logical Partitions.
Right-click the logical partition and select Configure Partitions. You are now working in the Configure Logical Partitions window.
Select the partition from which you would like to move memory.
Right-click Memory and select Move.
Specify the amount of memory to move in Memory to move. This value must be less than the current amount of memory available to the logical partition. The Memory after Move values for both the source and receiving partitions must fall within the minimum/maximum ranges specified for memory.
Select the partition to receive the memory in To logical partition.
Click OK to move the memory you specified.

To move memory from one logical partition to another using Management Central, follow these steps:

In iSeries Navigator, expand Management Central.
Expand Systems with Partitions.
Select the physical system that has the logical partition with which you want to work.
Right-click the logical partition and select Configure Partitions. You are now working in the Configure Logical Partitions window.
Select the partition from which you would like to move memory.
Right-click Memory and select Move.
Specify the amount of memory to move in Memory to move. This value must be less than the current amount of memory available to the logical partition. The Memory after Move values for both the source and receiving partitions must fall within the minimum/maximum ranges specified for memory.
Select the partition to receive the memory in To logical partition.
Click OK to move the memory you specified.

Parent topic:
Dynamically moving logical partition resources
Related concepts
Determining the amount of memory to move Restarting and powering down a system with logical partitions