If you use i5/OS® on a partitioned server, consider carefully how many software licenses are required for your logical partition configuration. Unique software resources exist and operate on hardware that is assigned to each logical partition. These software resources include separate copies of Licensed Internal Code, i5/OS, and other licensed programs. Additionally, language feature codes, security, user data, most system values, and software release and fixes also known as program temporary fixes (PTFs) remain unique for each logical partition.
The remainder of this article discusses i5/OS operating system licensing. Consult the documentation for the other licensed programs on your managed system to determine the licensing requirements for those programs.
The basic principle behind i5/OS licensing on IBM System i5™ and eServer™ i5 servers is that the managed system requires a single license for each physical processor that can run i5/OS. i5/OS licenses are obtained for the managed system as a whole, and not for individual logical partitions. This means that you never need to obtain more i5/OS licenses than the number of processors on the managed system.
The main complicating factor in calculating the number of i5/OS licenses that are required on a partitioned managed system is the fact that a logical partition that uses uncapped shared processors can use up to its assigned number of virtual processors. Depending on how you set the virtual processors on your i5/OS logical partitions, you might be required to obtain licenses for all of the processors in the shared processor pool. You might be required to do this even if the i5/OS logical partitions on your managed system are assigned only a small fraction of the processors in the shared processor pool.
The formula that is used to determine how many i5/OS licenses are required for a managed system is as follows:
| The total number of dedicated processors on i5/OS logical partitions that use dedicated processors. |
| PLUS |
The maximum number of shared processors that can be
used on i5/OS logical partitions
that use shared processors. This number is the lesser of the following two
values:
|
| EQUALS |
| The total number of i5/OS licenses required for the managed system. |
When you configure your managed system, ensure that the managed system is in compliance with your i5/OS license agreement. Minor configuration changes can cause the managed system to go out of compliance.
For example, Company Y has obtained three i5/OS licenses for a managed system with four processors and four logical partitions. All four logical partitions use the shared processing pool, so all four of the processors on the managed system are in the shared processing pool. The configuration of the logical partitions is as follows.
| 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 | i5/OS | Shared | Uncapped | 1.75 | 2 | 2.00 (the number of virtual processors for the uncapped shared logical partition) |
| Partition B | i5/OS | Shared | Capped | 0.60 | 1 | 0.60 (the number of processing units for the capped shared logical partition) |
| Partition C | i5/OS | 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) |
In this configuration, there are three i5/OS logical partitions on the managed system. The three i5/OS 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 i5/OS licenses, so the managed system is in compliance with the i5/OS license agreement.
It is very easy to go out of compliance with the i5/OS license agreement after making minor changes to the partition configuration. For example, 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 partition configuration.
| 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 | i5/OS | Shared | Uncapped | 1.75 | 2 | 2.00 (the number of virtual processors for the uncapped shared logical partition) |
| Partition B | i5/OS | Shared | Uncapped | 0.60 | 1 | 1.00 (the number of virtual processors for the uncapped shared logical partition) |
| Partition C | i5/OS | 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 i5/OS 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 i5/OS licenses, but requires a total of four i5/OS licenses, so the managed system is out of compliance with the i5/OS license agreement. Company Y will receive out-of-compliance messages for this managed system. Company Y must either contact IBM® to obtain one more i5/OS license for the managed system or reconfigure the processor settings so that the managed system requires only three i5/OS licenses once more.
As another example of how you can go out of compliance with the i5/OS license agreement after making minor changes to the partition configuration, 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 partition configuration.
| 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 | i5/OS | Shared | Uncapped | 2.25 | 3 | 3.00 (the number of virtual processors for the uncapped shared logical partition) |
| Partition B | i5/OS | Shared | Capped | 0.60 | 1 | 0.60 (the number of processing units for the capped shared logical partition) |
| Partition C | i5/OS | 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 i5/OS 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 i5/OS licenses, but requires a total of four i5/OS licenses, so the managed system is out of compliance with the i5/OS license agreement.
Licensing i5/OS logical partitions on IBM System p5™ and eServer p5 servers is more complex than it is on IBM System i5 and eServer i5 servers. You must obtain special licenses and feature codes to install and run i5/OS on IBM System p5 and eServer p5 servers. For more information on what you must obtain to use i5/OS on IBM System p5 and eServer p5 servers, see Requirements for i5/OS on IBM System p5 and eServer p5 servers