IBM & Red Hat on AWS

Transfer and Conversion of IBM Licenses When Migrating to AWS

Introduction

In this blog post, I will give an introductory overview of how IBM software licensing has been updated and how to associate and convert these IBM licensing concepts to Amazon Elastic Compute Cloud (Amazon EC2) types and usage. IBM is an AWS Premier Partner and has a wide portfolio of software products that are supported on or moving to AWS as well as being sold on-premises for its customers. When an IBM software customer considers using or moving to AWS with its IBM products, licensing is one of the factors that must be addressed.

IBM licensing overview

Recently, IBM has revamped its licensing processes overall, and also in terms of how their software licensing terms are applied when migrating to the AWS Cloud. These processes now cover migrations to modern, containerized environments as well as traditional migrations. While I will cover the major considerations below, you can find complete details in their Bring Your Own Software License guidebook.

The PVU Licensing Metric

A majority of IBM’s on-premises customers are using products that were licensed in terms of the power of the servers that they are hosted on, their “processor value”. The Processor Value Unit (PVU) is a metric that is used to determine the licensing cost of many IBM software products. It is based on the type of processor that is on the server where the software is installed, and enables IBM to reflect the product value based on the server’s potential performance — a slower. weaker server will cost less to use (in terms of PVUs) than a more powerful one. PVUs allow for a consistent licensing metric across changing server and virtualization technologies.

The number of required PVUs for a given product is based on the processor technology and the number of processors that are available to the software product. For PVU-based licensing, IBM defines an on-premises server processor as a processor core on a chip. For example, a dual-core processor chip has two processor cores. PVUs are assigned per core, not per processor.

The amount of PVUs assigned to a processor core is based on an IBM algorithm that takes the date of the technology, benchmark scores, and number of available sockets into account. Tables 1 and 2 below show example conversions:

Maximum Sockets Cores per Socket PVUs per Core Total PVUs
2 x8 x 70  =1120
4 x8 x 100  =3200
8 x8 x 120  =7680

Table 1: Example conversion table for 2- to 8-socket Intel processors into Processor Value Units (PVUs).

 Processor Model Maximum Sockets Cores per Socket PVUs per Core Total PVUs
POWER S822 2 8 x 70  = 1120
POWER E850 4 8 x 100  = 3200
POWER 880 8 8 x 120  = 7680

Table 2: Example conversion table for 2- to 8-socket POWER 8 processors into Processor Value Units (PVUs).

Virtualization is also taken into account when licensing software; a product running in a VM that is assigned 10 virtual cores (vCPUs on x86, see below) might only be licensed for 10 cores’ worth of PVUs, even if the server has more cores than that available on its processor.

The VPC License Metric

While the PVU is still a widely used license metric, IBM has been shifting to widely adopt Virtual Processor Core (VPC) licensing. The same IBM product may be now licensed on a PVU or VPC license. With IBM Cloud Pak products customer can now license products that were licensed on PVU terms as VPC-based solution bundles within related Cloud Paks.

A VPC is a unit of measurement based on the number of virtual cores (vCPUs) that are available to the product running in a VM on the server. A vCPU is a virtual core (on x86 architectures, a thread) that is assigned to a virtual machine, or a physical processor core if the server is not partitioned for virtual machines.

As an example, a an on-premises physical server may have 4 processor sockets, with each socket having 8 cores, for a total of 32 physical cores. This server may support 4 VMs, with each VM being assigned 10 vCPUs. An IBM product may be installed on one VM, with a license for 10 vCPUs. Ten (10) VPC license quantities will be required to license the 10 vCPUs. When licensed under VPC terms, the VPC license requirement for 10 vCPUs won’t change if moving to higher or lower processor power and server types. However if the customer is licensed under the PVU license metric, the PVU values needed may change. These vCPUs will have a PVU value based on the processor and server type.

RVUs

A Resource Value Unit (RVU) is used for measuring any other resource that a software product might be licensed against. An RVU might be an active user, a running software client, or an open data stream. The number and type of RVUs allowed is typically described in the software’s licensing terms, and may differ from customer to customer.

One example might be an IBM product installation where a total of 100 active (logged-in to the product) users are allowed at any given time.

License Tracking

IBM provides its License Metric Tool (ILMT) for tracking software inventory and PVU usage as a part of its licensing mechanisms. This tool’s agents and server are both supported on AWS, and are the IBM-required way to log PVU and VPC license usage.

ILMT runs on a “server-agent” model, where an ILMT server ins installed and takes in reports from agents installed on the systems where the software is running. IBM’s ILMT works in “hybrid” environments where the customer may have software both on-premises as well as on AWS; the server can be on-premise with agents in AWS, or the other way around. RVUs are not tracked or logged by this tool as they can be varied in terms.

Additionally, AWS License Manager can be used to self-manage PVU licensing; see the blog Track IBM license usage with AWS License Manager for details. There is no charge for either of these tools, though any AWS resource costs incurred for running the server and its agents will still need to be accounted for. The IBM License Monitoring Tool is still required in this scenario, and can be downloaded from the IBM License Metric Tool website.

Licensing and Containers

Many of the newly-launched IBM software packages on AWS make use of Kubernetes-based container clusters, in particular AWS’ Red Hat OpenShift Service on AWS (ROSA).

These products measure VPCs based on the maximum limit of the Amazon EC2 vCPUs (see below in AWS Terminology) assigned to the pods running the software. This is true whether on Amazon Elastic Kubernetes Service (EKS), Red Hat OpenShift, or ROSA.

One can then take that vCPU number and divide it by 2 to get the VPC total unless you are using M6g, A1, T2, or m3.medium instance types for OpenShift worker nodes (in which case total vCPUs = total VPCs). The IBM tool required to manage licenses for containers is different as well; IBM requires an additional Addendum to their licensing agreement and the use of the License Service in their Bring Your Own Software License guidebook.

AWS terminology

In Amazon EC2 instance terminology, a vCPU is the primary unit for counting processing capability. An Amazon vCPU is a thread of either an Intel Xeon core or an AMD EPYC core — excepting for AWS Graviton instance types, where one vCPU represents one core. For example, the Amazon EC2 m7i.4xlarge instance type offers 16 vCPUs.

Conversions

In IBM PVU licensing terms:

1 EC2 vCPU = 1 IBM VPC = 70 PVUs

So, when migrating a software product licensed for full-capacity of an Intel-based server with two sockets and four cores per socket (and thus 8 cores @ 70 PVUs per core), any combination of EC2 instances with a total of 8 vCPUs among them would be equivalent from a licensing perspective. Two m7i.xlarge or one m7i.2xlarge instance would meet the licensing goal, for example.

Another example might be a product running in an IBM POWER machine partition (called an LPAR, or “Logical Partition”), which partition has been assigned 20 cores out of the 64 cores available. In this example POWER model each core is rated at 120 PVUs, so the software would be licensed for at least 2400 (20 x 120) PVUs. A suitable EC2 instance configuration totalling 34 vCPUs (34 x 70 = 2380) would meet licensing obligations.

Please note that these conversion examples are using licensing units as a consideration, and actual workload requirements will also affect the type and number of EC2 instance types to be considered when working with the customer.

It is also possible to use AWS tools such as Auto Scaling to save expenses. Since PVU and VPC licensing is usually done on a “maximum allowed” basis, starting with a smaller configuration (such as a smaller number of EC2 instances) and setting a maximum scale amount (based on maximum PVU amount) may result in less resources being used on average and reducing cost. Another way to save licensing expenses, when the EC2 instance needed has more more cores than strictly necessary, is to use the instance launch options to customize vCPU availability.

Summary

In this post, I’ve described some of the licensing calculations to take into account when migrating IBM software from an on-premises to an AWS installation base. The reference tables and examples have shown how to calculate the PVU licensing requirements for a transition to an AWS install base. Reach out to your AWS contact and support team if you have questions about migrating IBM workloads to AWS.

References and Further Reading