Hardware discovery process on the HMC

Starting with the Hardware Management Console (HMC) Version 7 Release 3.2, and later, the HMC can use the hardware discovery process to capture additional information in a system plan about the hardware on a managed system.

Some systems have the capability to provide greater details about their hardware inventory through the process of hardware discovery. Hence, you can create a system plan with more extensive hardware information. By using the hardware discovery process, the HMC Version 7 Release 3.2, and later, can capture information about hardware that does not have a logical partition assignment and hardware with assignments to inactive logical partitions.

Note: If you create a system plan with the intention of converting the system plan for use in the System Planning Tool (SPT), you must use the latest version of the HMC to create the system plan. For example, to obtain disk-drive configuration information that the SPT can convert successfully in a system plan, you must use HMC Version 7 Release 3.3, or later, to have the hardware discovery process capture detailed disk-drive configuration information.

Additionally, the hardware discovery process writes hardware inventory information to a cache on the system. The hardware inventory cache ensures that a certain amount of hardware information is available on the system when you create a system plan. The HMC can use the data in this cache when you create a system plan to obtain more detailed hardware information for any logical partitions that are active at that time.

On a system that can use hardware discovery, the hardware discovery process runs whenever the system is powered on in hardware discovery mode. When you enable this option, the system powers on in a special mode that performs the hardware discovery process and records hardware inventory information to a cache on the system. This collected information is then available for use when you display data for I/O devices or when creating a system plan.

You also can run the hardware discovery process when you create a system plan. If the managed system is capable of hardware discovery, the Create System Plan page provides an option for running hardware discovery. By using this option called Retrieve inactive and unallocated hardware resources, you can capture hardware configuration information for the managed system, regardless of the state of the hardware. When using this option, the HMC uses both the data it collects from the updated inventory cache and the data it collects from the inventory gathering process as sources of information to create the system plan.

It is recommended that you use the Retrieve inactive and unallocated hardware resources option whenever you add or change the hardware while the new or changed hardware is deallocated from a partition. Otherwise, if the new or changed hardware is allocated to a partition, use this option to create the system plan when the partition is inactive. Doing so ensures that the inventory cache has the most current data possible.

The following figure shows how the hardware discovery process works when you select this option.

This image is a system-plan file that is created with both methods.

In the figure, the HMC uses the inventory gathering process to collect information about the active partitions and the hardware assigned to them. The HMC uses hardware discovery to collect information about the hardware assigned to the inactive IBM® i partition and about the unassigned hardware on the system. The HMC writes all the data collected by both processes to the system plan. The data collected through hardware discovery is also written to the inventory cache on the system. The HMC uses both sources of information to create the system-plan file.

When you create a system plan and do not select the Retrieve inactive and unallocated hardware resources option, the HMC does not perform a new hardware discovery. Instead the HMC uses the data in the inventory cache on the system. The HMC still performs inventory gathering and retrieves hardware information for any active logical partitions on the managed server. The resulting new system plan contains the hardware information that the HMC obtained from the inventory gathering process, and hardware information that the HMC obtained from the hardware inventory cache on the system.

The following figure illustrates how the hardware discovery process works when you do not select this option.

This image is a system-plan file that is created with inventory gathering only and data from the hardware cache.

In the figure, the HMC uses the inventory gathering process only to collect information about the inactive partition and the hardware assigned to it. The HMC completes the system plan by using hardware information from the inventory cache for the active logical partitions on the managed server.

Last updated: Wed, June 21, 2017