Software licensing for IBM licensed programs on logical partitions

If you use IBM® licensed programs such as AIX® and IBM i on a server with logical partitions, consider how many software licenses are required for your logical partition configuration. Careful consideration of your software might help minimize the number of software licenses that you must purchase.

Software license behavior varies by software product. Each solution provider has its own licensing strategy. If you use licensed programs from solution providers other than IBM, consult the documentation from those solution providers to determine the licensing requirements for those licensed programs.

With some servers, you can purchase IBM i licenses on a per-user basis. For more information about IBM i licenses, see Working with software agreements and licenses in the IBM i Knowledge Center..

Many IBM licensed programs allow you to purchase licenses based upon the number of processors that the licensed program uses on a managed system as a whole. An advantage of this processor-based licensing method is that it allows you to create multiple logical partitions without having to purchase separate licenses for each logical partition. Also, this method caps the number of licenses that you need for a managed system. You need never obtain more licenses for a single licensed program than the number of processors on the managed system.

The main complicating factor in calculating the number of licenses that are required on a managed system with logical partitions using processor-based licensing is the fact that a logical partition that uses uncapped shared processors can use up to its assigned number of virtual processors. When you use processor-based licensing, ensure that the number of virtual processors on uncapped logical partitions are set so that each IBM licensed program does not use more processors than the number of processor-based licenses that you have purchased for that IBM licensed program.

The number of licenses required for a single IBM licensed program on a managed system using processor-based licensing is the lesser of the following two values:
  • The total number of activated processors on the managed system.
  • The maximum number of processors that can be used by the IBM licensed program on the managed system. The maximum number of processors that can be used by the IBM licensed program on the managed system is the sum of the following two values:
    • The total number of processors assigned to all logical partitions that use dedicated processors and that run the IBM licensed program.
    • The sum of the maximum number of processing units that can run the IBM licensed program on each shared processor pool, rounded up to the next integer. The maximum number of processing units that can run the IBM licensed program on each shared processor pool is the lesser of the following two values:
      • The total number of processing units assigned to capped logical partitions that run the IBM licensed program, plus the total number of virtual processors assigned to uncapped logical partitions that run the IBM licensed program.
      • The maximum number of processing units specified for the shared processor pool. (For the default shared processor pool, this number is the total number of activated processors on the managed system minus the total number of processors assigned to all logical partitions that use dedicated processors and that are not set to share processors with shared processor logical partitions. Use of Capacity on Demand (CoD) can increase the number of activated processors on the managed system, which can cause the managed system to go out of compliance if you do not allow for CoD use. Also, if there are logical partitions that use dedicated processors, that run the IBM licensed program, and that are set to share processors with shared processor logical partitions, then you can deduct the processors for these dedicated processor logical partitions from the maximum number of processing units for the default shared processor pool total, because you have already counted these dedicated processors in the dedicated processor logical partition total.)

When you use processor-based licensing, ensure that the managed system is in compliance with the license agreement for each IBM licensed program that is installed on the managed system. If you have a managed system that can use multiple shared processor pools, you can use the multiple shared processor pool feature of the Hardware Management Console (HMC) to ensure that your managed system remains in compliance with these license agreements. You can configure a shared processor pool with a maximum processing unit value equal to the number of licenses that you have for your managed system, and then set all logical partitions that use the IBM licensed program so that they use that shared processor pool. The logical partitions in the shared processor pool cannot use more processors than the maximum processing unit value that is set for the shared processor pool, so the managed system remains in compliance with the per-processor license agreement.

For example, Company Y has obtained three processor-based IBM i licenses for a managed system with four processors and four logical partitions. The managed system has only one shared processing pool, and all four logical partitions use the shared processor pool, so all four of the processors on the managed system are in the shared processor pool. The configuration of the logical partitions is as follows.

Table 1. Logical partition configuration in compliance with license agreement
Logical partition name Operating system Processing mode Sharing mode Processing units Virtual processors Maximum number of processors that can be used by the logical partition
Partition A IBM i Shared Uncapped 1.75 2 2.00 (the number of virtual processors for the uncapped shared logical partition)
Partition B IBM i Shared Capped 0.60 1 0.60 (the number of processing units for the capped shared logical partition)
Partition C IBM i Shared Capped 0.40 1 0.40 (the number of processing units for the capped shared logical partition)
Partition D Linux Shared Uncapped 1.25 2 2.00 (the number of virtual processors for the uncapped shared logical partition)

This configuration has three IBM i logical partitions and one Linux logical partition on the managed system. The three IBM i logical partitions can use a maximum of 3.00 processors (2.00 for Partition A, 0.60 for Partition B, and 0.40 for Partition C). The managed system has three IBM i licenses, so the managed system is in compliance with the IBM i license agreement.

For an example of a logical partition configuration that is out of compliance with a licensing agreement, the system administrator at Company Y changes the sharing mode of Partition B and Partition C from capped to uncapped. The following table shows the new logical partition configuration.

Table 2. Logical partition configuration out of compliance with license agreement (first example)
Logical partition name Operating system Processing mode Sharing mode Processing units Virtual processors Maximum number of processors that can be used by the logical partition
Partition A IBM i Shared Uncapped 1.75 2 2.00 (the number of virtual processors for the uncapped shared logical partition)
Partition B IBM i Shared Uncapped 0.60 1 1.00 (the number of virtual processors for the uncapped shared logical partition)
Partition C IBM i Shared Uncapped 0.40 1 1.00 (the number of virtual processors for the uncapped shared logical partition)
Partition D Linux Shared Uncapped 1.25 2 2.00 (the number of virtual processors for the uncapped shared logical partition)

In this configuration, the three IBM i logical partitions can use a maximum of 4.00 processors (2.00 for Partition A, 1.00 for Partition B, and 1.00 for Partition C). The managed system has only three IBM i licenses, but requires a total of four IBM i licenses, so the managed system is out of compliance with the IBM i license agreement.

If you have a managed system that can use multiple shared processor pools, you can use the Hardware Management Console (HMC) to configure a shared processor pool with a maximum processing unit value of 3.00, and assign Partition A, Partition B, and Partition C to that shared processor pool. If you do this, Partition A, Partition B, and Partition C can continue to be uncapped. You would remain in compliance with the IBM i license agreement, because the maximum processing unit value would ensure that IBM i uses no more than three processing units.

For another example of a logical partition configuration that is out of compliance with a licensing agreement, the system administrator at Company Y changes the sharing mode of Partition B and Partition C back to capped. However, the system administrator then moves 0.50 processing units from Partition D to Partition A. Before the system administrator is allowed to do this, the system administrator must increase the number of virtual processors on Partition A from 2 to 3. The following table shows the new logical partition configuration.

Table 3. Logical partition configuration out of compliance with license agreement (second example)
Logical partition name Operating system Processing mode Sharing mode Processing units Virtual processors Maximum number of processors that can be used by the logical partition
Partition A IBM i Shared Uncapped 2.25 3 3.00 (the number of virtual processors for the uncapped shared logical partition)
Partition B IBM i Shared Capped 0.60 1 0.60 (the number of processing units for the capped shared logical partition)
Partition C IBM i Shared Capped 0.40 1 0.40 (the number of processing units for the capped shared logical partition)
Partition D Linux Shared Uncapped 0.75 2 2.00 (the number of virtual processors for the uncapped shared logical partition)

In this configuration, the three IBM i logical partitions can use a maximum of 4.00 processors (3.00 for Partition A, 0.60 for Partition B, and 0.40 for Partition C). The managed system has only three IBM i licenses, but requires a total of four IBM i licenses, so the managed system is out of compliance with the IBM i license agreement.

Considerations other than licensed program agreements might constrain your ability to run IBM licensed programs on certain server models.




Last updated: Fri, July 05, 2019