Changing processor settings
You can view and change the settings of the shared and dedicated processors that are assigned to a partition by using the Hardware Management Console (HMC).
You can change the number of virtual processors and processing units that are assigned to the partition. The views and controls that are displayed depend on whether the processor is dedicated or shared, or running or stopped.
You can set a partition to use either processors that are dedicated to the partition or processors that are shared with other partitions. If a partition uses dedicated processors, you must allocate processors (in increments of whole numbers) to the partition. A partition that uses dedicated processors cannot use any processing capacity beyond the processors that are assigned to the partition.
By default, all physical processors that are not dedicated to specific partitions are grouped in a shared processor pool. You can allocate a specific amount of the processing capacity in this shared processor pool to each partition that uses shared processors. With some models, you can use the HMC to configure multiple shared processor pools. These models have a default shared processor pool that contains all the processor resources that do not belong to partitions that use dedicated processors or partitions that use other shared processor pools. The other shared processor pools on these models can be configured with a maximum processing unit value and a reserved processing unit value. The maximum processing unit value limits the total number of processors that can be used by the partitions in the shared processor pool. The reserved processing unit value is the number of processing units that are reserved for the use of uncapped partitions within the shared processor pool.
You can set a partition that uses shared processors to use a minimum of 0.10 processing units, which are approximately a 10th of the processing capacity of a single processor. When the firmware is at level 7.6, or later, you can set a partition that uses shared processors to use a minimum of 0.05 processing units, which are approximately a 20th of the processing capacity of a single processor. You can specify the number of processing units to be used by a shared processor partition to the 100th of a processing unit. In addition, you can set a shared processor partition such that, if the partition requires more processing capacity than its assigned number of processing units, the partition can use processor resources that are not assigned to any partition or processor resources that are assigned to another partition but that are not being used by the other partition. Some server models might require you to enter an activation code before you can create partitions that use shared processors.
If the operating system and server model supports, you can allocate up to the entire processing capacity on the managed system to a single partition. You can configure your managed system such that it does not comply with the software license agreement for your managed system. However, if you operate the managed system in such a configuration, you might receive out-of-compliance messages.
Shared processors are physical processors that share processing capacity among multiple partitions. The ability to divide physical processors and share them among multiple partitions is known as the Micro-Partitioning® technology.
Partitions that use shared processors can have a sharing mode of capped or uncapped. An uncapped partition is a partition that can use more processor power than its assigned processing capacity. The amount of processing capacity that an uncapped partition can use is limited only by the number of virtual processors that are assigned to the partition or the maximum processing units that are allowed by the shared processor pool that the partition uses. In contrast, a capped partition is a partition that cannot use more processor power than its assigned processing units.
Dedicated processors are whole processors that are assigned to a single partition. If you choose to allocate dedicated processors to a partition, you must allocate at least one processor to that partition. Likewise, if you choose to remove processor resources from a dedicated partition, you must remove at least one processor from the partition. On systems that are managed by an HMC, dedicated processors are assigned to partitions that use partition profiles.
A virtual processor is a representation of a physical processor core to the operating system of a partition that uses shared processors.
- Choose one of the following navigation options depending on the interface type of the Hardware Management Console (HMC):
- If you are using an HMC Enhanced interface, complete the following steps:
- In the navigation pane, expand .
- Select the server on which the logical partition is located.
- Select Manage by using one of the following options:
- Click the menu next to the partition name and select Manage. The Manage page opens.
- In the work pane, select Manage. The Manage page opens.
- If you are using an HMC Enhanced+ interface, complete the following steps:
- In the navigation pane, click the Resources icon
. - Click All Systems. The All Systems page is displayed.
- In the work pane, select a system and click . In the Partitions page, you can view all the partitions that belong to the system.
- In the work pane, select the partition for which you want to view or change the properties and capabilities and click . The Properties page is displayed. You can view and change the properties that are listed under the Properties area.
- In the navigation pane, click the Resources icon
- If you are using an HMC Enhanced interface, complete the following steps:
