Sub-Capacity Licensing with IBM PVU, IBM VPC, and IBM Cloud Pak

IT Asset Management (Cloud)
When an application runs on a virtual machine, some licenses take into account the kind of server the virtual machine is running on. In those cases, the license rules might require that either:
  • The application on the virtual machine must be licensed for the full power of the underlying host (such as counting all its processors, or cores, or threads to work out how many points/entitlements to consume from the license). This is called full capacity licensing.
  • The license may take account only of that fraction of the capacity of the host server that is assigned to the virtual machine. For example, on a 16-core host server, a particular virtual machine may be limited to using only 2 cores. You then work out the license consumption using only that fraction of the host server's capacity, and this is called sub-capacity licensing.
Both IBM PVU and IBM VPC licenses support both full capacity and sub-capacity licensing. IBM have tight requirements in their license agreements for sub-capacity licensing. Most basically, you must choose between:
  • Using ILMT (or related IBM tools like IBM SUA, Tivoli Asset Discovery for Distributed [TAD4D], and IBM BigFix Inventory — for simplicity this chapter focuses on ILMT). For IBM PVU licenses, this option includes the possibility of importing peak values from ILMT to incorporate them into your global license management view within IT Asset Management. (For IBM VPC licenses, there is no import of license consumption results from ILMT – although of course ILMT remains available as an inventory source.)
  • Using IT Asset Management to calculate sub-capacity license consumption for the current reporting period.
Note: You cannot combine sub-capacity calculations from both ILMT and IT Asset Management at the same time — one or the other is the source of truth at any moment. The following points apply:
  • When ILMT is the source of truth, calculations made by IT Asset Management are (and must always be) at the full capacity of each host. However, when you import IBM PVU results from ILMT into IT Asset Management, the sub-capacity results imported from ILMT for any device are used for license consumption in preference to full capacity consumption for the same device.
  • Although there can only be a single source of truth at any moment, you can of course switch over from one to the other at a moment of your choosing. Such a change-over does not even need to coincide with a boundary of a reporting period, as described later in this chapter.
  • When IT Asset Management is the source of truth, you may continue to import results from ILMT if you wish. These results are also sub-capacity results, since ILMT only exports sub-capacity results. However, results calculated by IT Asset Management are, in this case, always used for license consumption. The only purpose of importing ILMT results when IT Asset Management is the source of truth is to allow comparison of IBM PVU sub-capacity results from the two systems.
    Tip: It is not uncommon to find differences between the two systems. This is because sub-capacity consumption results show the peak value (summed across three mandatory 'regions' declared by IBM) over time, and the times used are different:
    • ILMT exports the peak values for all time. (This is different from the results displayed within ILMT, which are the peaks for the current reporting period.)
    • IT Asset Management recalculates daily the peak values for the current reporting period, taking into account your latest data corrections (as discussed later).
    Therefore, if you had a peak value in Asia/Pacific region in 2015, and since then you have adjusted your configuration so that consumption is much lower, IT Asset Management reports your lower peak for the current reporting period (typically a 3 months' rolling window), while ILMT still exports the higher peak from years ago. For an apples-to-apples comparison, then, it's best to compare the values visible within ILMT with those calculated by IT Asset Management.

This chapter first gives you a high-level overview of the requirements for the two approaches, to help you make the technology choice (see Two Ways to Collect Inventory).

However, for many enterprises, this is not so much an "either-or" question as it is a "both-and", or more precisely, first one and then the other. Therefore the chapter next provides a conceptual framework for understanding the overall process of transitioning from one tool to the other (see Understanding the Transition).

Whether you are implementing just one approach, or are changing over from one to the other, there is a lot of overlap in required actions and detailed processes. Because of the overlap, the remaining topics in the chapter can be read from either point of view:
  • If you are implementing only one approach, choose either Using ILMT (and Importing Results) or Using IT Asset Management, and step through the procedures there, ignoring any sections about transitioning tasks.
  • If you are changing from ILMT to IT Asset Management, you may use all the topics in the order provided to ensure a smooth transition and an effective outcome.

IT Asset Management (Cloud)

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