Hardware Management Console Installation and Operations Guide


Preparing for Partitioning

This chapter helps you prepare for a multiple-partitioned environment, including information about requirements, host name considerations, and managed system operating states.


Partitioning Requirements

This section contains information about the requirements you must have in order to create partitions.

Overall Requirements

You should do the following before creating partitions:

Before you start using partitioning, you must determine the following:

Assignable Resources for Logical Partitioning

For logical partitions, you must assign resources by creating partition profiles. Use the following guidelines for assigning resources in logical partition profiles.

Processors

Each processor installed and configured on your system can be individually assigned to a logical partition. You must assign at least one processor to each logical partition.

Memory

The HMC can assign memory to a logical partition in increments of 256 MB, with a minimum of 256 MB per partition. One GB is equal to 1024 MB. This section describes the HMC's various logical partition memory considerations.

Logical Partition Memory Usage

The system requires some memory overhead when it creates logical partitions. Use the following table to help you determine how much memory overhead the system needs for partitioning. You can also use this table to determine the maximum number of partitions you can create.

Total Memory (in GB) Approx. Memory Overhead (in GB) Approx. Usable Partition Memory (in GB) Maximum Number of Partitions:

AIX or Linux, any version

Pre-10/2002 firmware

<=16GB and >16GB

(see Notes 1 and 2)

Maximum Number of Partitions:

AIX 5.1

Post-10/2002 Firmware

<=16GB and >16GB

(see Notes 1 and 3)

Maximum Number of Partitions:

AIX 5.2 (+) or Linux

Post-10/2002 firmware

All partition sizes

(see Notes 1, 4, and 5)

4 .75 to 1 3 to 3.25 3 and 0 13 and 0 13
8 .75 to 1 7 to 7.25 6 and 0 16 and 0 16
16 .75 to 1 15 to 15.25 14 and 0 16 and 0 16
24 1 to 1.25 22.75 to 23 16 and 0 16 and 0 16
32 1 to 1.25 30.75 to 31 16 and 0 16 and 0 16
48 1.25 to 1.75 46.25 to 46.75 16 and 1 16 and 1 16
64 1.5 to 2 62 to 62.5 16 and 2 16 and 2 16
96 2 to 2.5 93.5 to 94 16 and 4 16 and 4 16
128 2.5 to 3.5 124.5 to 125.5 16 and 6 16 and 6 16
192 3.5 to 4.5 187.5 to 188.5 16 and 10 16 and 10 14
256 5 to 6 250 to 251 16 and 14 16 and 14 16

Notes:

  1. All partition maximums are subject to availability of sufficient processor, memory, and I/O resources to support that number of partitions. For example, a system with only 8 processors can only support a maximum of 8 partitions

  2. These rules apply to systems running partitions with any version of AIX or Linux, if the firmware and HMC release levels are earlier than the 10/2002 release level.

  3. These rules apply to systems running partitions with AIX version 5.1, if the firmware and HMC release levels are at the 10/2002 release level or later. The HMC partition profile option for "Small Real Mode Address Region" option should not be selected for AIX 5.1 partitions. These numbers reflect the maximum when running only AIX 5.1 partitions, but AIX 5.1 and 5.2 partitions can be mixed, and may allow for additional partitions to be run (up to the maximum of 16).

  4. These rules apply to systems running partitions with AIX version 5.2 (or greater) or Linux, if the firmware and HMC release levels are at the 10/2002 release level or later. The HMC partition profile option for "Small Real Mode Address Region" should be selected for these partitions.

  5. AIX 5.2, when run with the Small Real Mode Address Region profile option, requires that the maximum memory setting is no greater than 64 times the minimum memory setting. For example, if the minimum memory setting is 256MB, then the maximum memory setting should not be greater than 16GB. If you violate this condition, AIX does not start.

Real Mode Address Region (RMO) Memory Considerations

There are some special memory options to consider when assigning memory to a partition.

Small Real Mode Address Region

When you create a partition profile and select the memory sizes, you can select a box called Small Real Mode Address Region. This option allows you to:

To use the Small Real Mode Address Region option, you must have either Linux or AIX 5.2 installed in the partition. If you check the Small Real Mode box and have the required operating system on your partition, you do not have to follow the following memory boundary rules.

AIX 5.1 may not boot in a partition with the Small Real Mode Address Region option selected, because AIX 5.1 requires a Real Mode Address Region that scales with the size of the overall partition. If you meet these operating system requirements and check the Small Real Mode Address Region box, then the following memory allocation restrictions do not apply.

Large Real Mode Address Region

If you do not select the Small Real Mode Address Region option, then when you assign your minimum, desired, and maximum memory amounts in the partition profile, all three memory values will be constrained to be within a specific range. Each range is associated with a scalable Real Mode Address Region of a particular size (256 MB, 1 GB, and 16 GB). The Real Mode Address Region size is automatically determined by the maximum partition memory size that you specify. These memory ranges are defined in the following table:

Maximum Memory Size (in GB) Real Mode Address Region size (in GB) Partition Memory Range (in GB)
Up to 4 .25 .25 to 4
4.25 to 16 1 1 to 16
16.25 to 256 16 16 to 256

Because large Real Mode Address Regions have more constraints when placed in memory, use the following guidelines when you are planning to create partitions that do not use the Small Real Mode Address Region option:

I/O Devices

I/O is assignable to a given partition on a PCI adapter-slot basis.

Because each partition requires its own separate boot device, the system must have at least one boot device and associated adapter per running partition.

Each partition should have at least one network adapter, although this is not mandatory. In addition to providing a network connection, the connection is also needed to provide the capability for HMC service functions. For more information , see Customizing Network Settings.

For more information about a specific device and its capabilities, see the documentation shipped with that device. For a list of supported adapters and a detailed discussion about adapter placement, refer to the PCI Adapter Placement Reference, order number SA38-0538.

Assignable Resources for Affinity Partitioning

You must assign I/O resources to your affinity partitions by creating partition profiles.

Processors and Memory

The HMC pre-allocates processors and memory to affinity partitions. You can choose to create either 4-processor affinity partitions or 8-processor affinity partitions. If you have 32 processors on your system, choosing a 4-processor group allows you to create up to eight affinity partitions. Likewise, an 8-processor group allows you to create up to four affinity partitions. You cannot define 4-processor groups and 8-processor groups at the same time.

I/O Devices

The user allocates I/O to each affinity partition. I/O is assignable to a given partition on a PCI adapter-slot basis. You can also dynamically reassign I/O between affinity partitions.

Because each partition requires its own separate boot device, the system must have at least one boot device and associated adapter per partition.

Each partition should have one network adapter, although this is not mandatory. In addition to providing a network connection, the connection is also needed to provide the capability for HMC service functions. For more information , see Customizing Network Settings.

For more information about a specific device and its capabilities, see the documentation provided with that device. For a list of supported adapters and a detailed discussion about adapter placement, refer to the PCI Adapter Placement Reference, order number SA23-2504.


Assigning a Host Name to Your Partition

Each partition, including the Full System Partition, must have a unique host name that can be resolved. Host names cannot be reused between the Full System Partition and the logical partitions. If you need to change the the host name of the partition manually, you may need to update the Network Settings on the HMC. You will need to update if a "short" partition name is used or if a DNS server is not used. For more information about changing the host name manually, seeChanging a Partition Host Name Manually. See Customizing Network Settings to determine if any additional changes are needed.


Operating States

The HMC Contents area displays an operating state for the managed system.

Operating States for Managed Systems

The following operating states apply to the managed system:

State Description
Initializing The managed system is powered on and is initializing.
Ready The managed system is powered on and operating normally.
No Power The managed system is powered off.
Error The managed system's operating system or hardware is experiencing errors.

For recovery information, see Managed System Operating States.

Incomplete The HMC cannot gather complete partition, profile, or resource information from the managed system.

For recovery information, see Managed System Operating States.

No Connection The HMC cannot contact the managed system.

For recovery information, see Managed System Operating States.

Recovery The partition and profile data stored in the managed system must be refreshed.

For recovery information, see Managed System Operating States.

Version Mismatch Your managed system's service processor level is higher than your HMC's code level.

For recovery information, see Managed System Operating States.

CUOD CTA You must accept the CUoD license.

For recovery information, see Managed System Operating States.

Operating States for Partitions

The following operating states apply to the logical partition you have created.

State Description
Ready The partition is not active but is ready to be activated.
Starting The partition is activated and is undergoing booting routines.
Running The partition has finished its booting routines. The operating system might be performing its booting routines or is in its normal running state.
Error This partition failed to activate due to a hardware or operating system error.

For recovery information, see Appendix C, Error Messages and Recovery Information.

Not Available This partition is not available for use. Reasons can include:
  • The managed system is powered off.
  • The Full System Partition is not available when the managed system is powered on with the Partition Standby power-on option.
  • Logical partitions are not available when the managed system is powered on with the Full System Partition power-on option.
  • Affinity partitions are not available when the managed system is powered on and non-affinity partitions are activated first.
  • Non-affinity partitions are not available when the managed system is powered on and affinity partitions are powered on first.

For recovery information, see Appendix C, Error Messages and Recovery Information.

Open Firmware The partition was activated by a profile that specified an OPEN_FIRMWARE boot mode.


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