Partition profile

A partition profile is a record on the Hardware Management Console (HMC) that specifies a possible configuration for a logical partition. When you activate a logical partition using a partition profile, the managed system attempts to start the logical partition using the configuration information in the partition profile.

A partition profile specifies the desired system resources for the logical partition and the minimum and maximum amounts of system resources that the logical partition can have. The system resources specified within a partition profile includes processors, memory, and I/O resources. The partition profile can also specify certain operating settings for the logical partition. For example, you can set a partition profile so that, when the partition profile is activated, the logical partition is set to start automatically the next time that you power on the managed system.

Each logical partition on a managed system that is managed by an HMC has at least one partition profile. If desired, you can create additional partition profiles with different resource specifications for your logical partition. If you create multiple partition profiles, you can designate any partition profile on the logical partition to be the default partition profile. The HMC activates the default profile if you do not select a specific partition profile to be activated. Only one partition profile can be active at one time. To activate another partition profile for a logical partition, you must shut down the logical partition before you activate the other partition profile.

A partition profile is identified by the logical partition ID and partition profile name. Logical partition IDs are whole numbers used to identify each logical partition that you create on a managed system, and partition profile names identify the partition profiles that you create for each logical partition. Each partition profile on a logical partition must have a unique partition profile name, but you can use a partition profile name for different logical partitions on a single managed system. For example, logical partition 1 cannot have more than one partition profile with a partition profile name of normal, but you can create a normal partition profile for each logical partition on the managed system.

When you create a partition profile, the HMC shows you all of the resources available on your system. The HMC does not verify if another partition profile is currently using a portion of these resources. Therefore, it is possible for you to over commit resources. When you activate a logical partition using a partition profile, the system attempts to start the logical partition using the resources that are specified in the partition profile. If the minimum resources specified in the partition profile are not available on the managed system, the logical partition cannot be started using the partition profile.

For example, you have four processors on your managed system. Logical partition 1 with partition profile A has three processors, and logical partition 2 with partition profile B has two processors. If you attempt to activate both of these partition profiles at the same time, logical partition 2 with partition profile B fails to activate because you have over committed processor resources.

When you shut down a logical partition and reactivate the logical partition using a partition profile, the partition profile overlays the resource specifications of the logical partition with the resource specifications in the partition profile. Any resource changes that you made to the logical partition using dynamic partitioning are lost when you reactivate the logical partition using a partition profile. This is desirable when you want to undo dynamic partitioning changes to the logical partition. However, this is not desirable if you want to reactivate the logical partition using the resource specifications that the logical partition had when you shut down the managed system. It is therefore best to keep your partition profiles up to date with the latest resource specifications. You can save the current configuration of the logical partition as a partition profile. This allows you to avoid having to change partition profiles manually.

If you shut down a logical partition whose partition profiles are not up to date, and the logical partition is set to start automatically when the managed system starts, you can preserve the resource specifications on that logical partition by restarting the entire managed system using the partition autostart power-on mode. When the logical partitions start automatically, the logical partitions have the resource specifications that the logical partitions had when you shut down the managed system.

You must activate a logical partition by activating a partition profile at least once. After that, you can activate the logical partition based on its current configuration data that is saved in the hypervisor. Logical partitions start faster when activated based on their current configuration data than when activated with a partition profile.