3.33 min to readAsset ManagementPublisher Advisory Services

How to count your IBM licenses in hyper-threaded public cloud environments?

Randy BalSolution Consultant for IBM Software
Asset Management

IBM provides various metrics for licensing and measuring the usage of its software programs. The most common used metric is the capacity-based metric. IBM programs licensed on this metric requires you to license the amount of processing capacity assigned to the IBM program and is expressed in:

  • PVU (Processor Value Unit): Number of processors cores * processor weight
  • VPC (Virtual Processor Core): Number of processor cores
  • RVU MAPC (Resource Value Unit Managed Active Processor Core)

For all these metrics, an approved tool like IBM LMT, HCL BigFix Inventory or Flexera One is mandatory to be used (as of May 2022) to be sub-capacity eligible. More information on this can be found here.

The proper installation, configuration and use of one of these tools is required on any platform if you want to license an IBM program at the sub capacity (virtual capacity) of the server. IBM provides support for on-premises platforms like VMware, MS HyperV, AIX and Public Cloud Platforms such as Microsoft Azure, Amazon, IBM and Google.

Hyper threaded cores ignored on on-prem platforms

ILMT, BigFix Inventory and Flexera One determine the number of assigned processor-capacity based on the information it can extract from the following two sources:

  1. Operating system (e.g.: Windows 2019 Server) which reports the number of processors made available to the Operating System and
  2. Hypervisor environment (e.g.: VMware VCenter) where it extracts the physical processor type, number of sockets and number of cores which are assigned to the VM

IBM defines a processor core to be "each physical processor core on a chip". When hyperthreading is enabled, the Operating System reports the double amount of CPUs compared to the actual amount of cores available. Hyperthreading is a feature which can be enabled in the BIOS and can improve the performance of the CPU. Basically, hyperthreading splits the CPU in two or more threads (often referred as logical CPUs, LCPUs) and allows the CPU to execute multiple tasks at the same time.

Fortunately, using the information Hypervisor environment, ILMT, BigFix Inventory and Flexera One are able to determine the actual number of physical cores assigned and ignores the hyperthreaded cores (LCPUs)

Measuring in eligible cloud environments

The way processor core capacity is measured is slightly different on an Eligible Cloud Platform. A tool like ILMT is still mandatory for reporting at the sub-capacity of the server. However, ILMT cannot determine the exact assigned processor type since access to the Hypervisor environment is prohibited by the Cloud Provider.

To continue to support IBM programs on Public Cloud Platforms, IBM decided to count each processor core visible in the operating system as 1 Core and require 1 VPC or 70 PVU license(s). Instead of configuring a connection to a Hypervisor in ILMT, tags are required to identify these VM’s. (1 vCPU = 1 Core = 1 VPC = 70 PVUs)

Hyper threaded cores are counted on on-prem platforms

Microsoft provides a large list of different VM sizes and configurations on Microsoft Azure which is an IBM Eligible Public Cloud platform. These VMs vary in CPU, memory and disk but Microsoft also provides Hyper-Threaded and AMD Simultaneous multithreading technology. More information on this can be found here

Take for example VM Type: DS_v3. DS_v2. This VM offers a VCPU:CORE ratio of 2:1, which means that, identical to an on-premises VM, the 2 cores presented in the Operating System are supported by a single CPU-core.

You probably assume that ILMT applies the same calculation method, right?

Unfortunately, since access to the hypervisor is prohibited, the tools cannot determine if the cores presented in the Operating Systems are actual processor cores or are CPU threads (LCPUs). This means that in this scenario, ILMT counts the 2 logical cores as 2 processor cores (2 * 70 PVU = 140PVU) on Azure but in fact only one physical processor core is allocated to this VM.

What does this mean for you?

A transformation to the cloud may result in different license requirements than you may initially expect. To avoid unpleasant and unexpected costs at the start, during and/or after your transformation to the cloud, a clear view of your current licensing position is required. Reach out to us to learn more on how we can support you best.

Be in control of your IBM licensing in the public cloud

When moving to the cloud, sometimes your initial plan doesn’t align with reality. Avoid unexpected costs and risk by working with IBM professional consultants.

Be in control of your IBM licensing in the public cloud

When moving to the cloud, sometimes your initial plan doesn’t align with reality. Avoid unexpected costs and risk by working with IBM professional consultants.

Get in touch

Randy Bal
Solution Consultant for IBM Software