Creating a shared memory partition

The process to create a shared memory partition is similar to creating a partition with the dedicated memory. The only difference is in the memory section of the Create LPAR wizard, where you must select the shared memory for the partition.

The following procedure creates a shared memory pool with a size of 20 GB and nine paging devices. Paging devices are disks provided through a storage area network (SAN) and mapped on two Virtual I/O Server (VIOS) partitions. A paging device is required for each shared memory partition for the shared memory pool to accommodate nine shared memory partitions.

To create the shared memory partition, complete the following steps:

1. Open the Create LPAR wizard and navigate to the Memory window.
2. Select Shared and click Finish.
3. Click Next to continue. The Memory Settings window is shown.
4. Enter the amount of logical memory that you want to activate the partition in the Minimum Memory field.
5. Enter the amount of logical memory that you want for the partition in the Desired Memory field.
6. Enter the maximum amount of logical memory that you want to be assigned to the partition by using dynamic logical partition (DLPAR) in the Maximum Memory field.
7. Change the Custom Entitled Memory field only if you have specific requirements regarding the I/O devices. The Custom Entitled Memory field defines the amount of memory that is permanently allocated in the memory pool to handle the I/O activities.
8. Select one or two paging VIOS partitions for redundancy.

   When using two VIOS partitions, VIOS 1 is set as the primary paging VIOS partition for this partition and is used to handle the paging activity. In case of failure, the hypervisor switches to the secondary paging VIOS partition. Because primary and secondary paging VIOS partitions are defined at the partition level, you can load balance the paging workload on both the VIOS partitions by defining different paging VIOS partitions on each partition. For partitions using dual VIOS partitions, you must make sure that redundant paging devices are available.

9. Enter the memory capacity weight you want in the Memory Capacity Weight field. The memory capacity weight is used by the hypervisor to determine which shared memory partition receives more memory from the shared memory pool. If the setting is higher, the possibilities are more for the partition to get physical memory.
10. Enter the active memory expansion factor you want in the Active memory expansion factor field.
11. Click Finish and Next to continue to navigate further.