Tuesday, April 19, 2011

HMC & LPAR Short Notes


HMC device is required to perform LPAR , DLPAR and CUOD configuration and management.

A single HMC can manage 48 i5 systems and 254 LPARs

In a partition there is a maximum no. of 64 virtual processors.

A mix of dedicated and shared processors within the same partition is not supported.

Sharing a pool of virtualized processors is known as Micro Partitioning technology

The maximum no.of physical processors on p5 is 64.

In Micro partition technology the minimum capacity is 1/10 processing units.

Virtual Ethernet enables inter partition communication without a dedicated physical network adapter.

The virtual IO server owns the real resources that are shared with other clients.

Shared Ethernet adapter is a new service that acts as a layer 2 network switch to route network traffic from a virtual Ethernet to a real network adapter.

On p5 – 595 Max no.of processors- 64, Max Memory Size – 2TB, Dedicated processor partitions-64, Shared processor partitions- 254.

HMC model for p5 – 595 is 7310-C04 or 7310-CR3

HMC Functions: LPAR, DLPAR, Capacity on demand without reboot, Inventory and microcode management, Remote power control.

254 partitions supported by one HMC.

A Partition Profile is used to allocate resources such as processing units, memory and IO cards to a partition. Several partition profiles may be created for the same partition.

System profile is a collection of partition profiles. A partition profile cannot be added to a system profile if the partition resources are already committed to another partition profile.

To change from one system profile to another, all the running partitions must be shutdown.

To find the current firmware level: lscfg –vp |grep –p ‘Platform Firmware:’

Simultaneous multi threading : The instructions from the OS are loaded simultaneously into the processor and executed.

DLPAR : DLPAR allows us to add, move or remove processors, memory and IO resources to, from or between active partitions manually without having to restart or shutdown the partition.

Unused processing units available in shared processor pool.

Dedicated processors are whole processors that are assigned to a single partition. The minimum no. of dedicated processors you must assign is one processor.

When a partition with dedicated processors is powered down, their processors will be available to the shared processor pool. This capability is enabled by “Allow idle processors to be shared”.

Idle processors from active partitions with dedicated processors can be used by any uncapped partition that requires additional processing units to complete its jobs.

Shared processor minimum processing unit is 0.1

Capped : The processor usage never exceeds the assigned processing capacity.

Uncapped : Processing capacity may be exceeded when the shared processor pool has spare processing units.

Weight is a number range between 0-255. If there are 3 processors available in the shared processor pool , partition A has an uncapped weight of 80 and B has 160. The LPAR A will receive 1 processing unit and B receive 2 processing units.

Minimum Memory is the minimum amount of memory which needed by the logical partition to start.

Desired memory is the requested amount of memory for the partition. The partition will receive an amount of memory between minimum and desired. Desired memory is the amount of memory which LPAR needs to have when the lpar is powered on. If the managed system does not have the desired amount of memory but only has lesser memory , those uncommitted memory resources will be assigned to the LPAR when the LPAR is activated.

You cant increase the memory more than maximum value.

Installed memory is the total no. of memory units that are installed on the managed system

Creating a new LPAR :

Server and Partition à Server Management à right click partitionsà Createà logical partition

Give partition ID(Numeric between 1 and 254) and name (max 31 characters)

Give partition type (AIX or linux, i5/OS, VIO)

Select work load management group NO

Give profile name

Specify the Min, Desired and Max memory

Select the dedicated/shared processors

If you select dedicated then give min,desired and max processors

If you select the shared give min,desired and max processing units and click advanced

And click the radio button(capped/uncapped) and give the virtual processors(min,max,desired)

If you select the uncapped give the weight also.

Allocate physical IO resources : Select the IO and click the add as required/add as desired.

IO resources can be configured as required or desired. A required resource is needed for the partition to start when the profile is activated. Desired resources are assigned to the partition if they are available when the profile is activated.

And select the console, location code

To create another profile Right click the partition à createà profileà give profile id.

Change default profile : Right click the partition àchange default profileà choose profile.

Restart options :

DUMP : Initiate a main storage or system memory dump on the logical partition and restart the logical partition when complete.

Immediate : as quickly as possible , without notifying the logical partition.

DUMP Retry : Retry a main storage or system memory dump on the logical partition and restart the logical partition when complete.

Shutdown options :

Delayed : Shutdown the logical partition by starting the delayed power off sequence.

Immediate : as quickly as possible , without notifying the logical partition.


DLPAR can be performed against the following types :

Physical Adapters



VIO Adapters

Right click the partition à Dynamic Logical Partitioningà Physical adapter resourcesà add/move/remove

Licensed Internal Code Updates: To install licensed internal code fixes on your managed systems for a current release click “change licensed internal code for the current release”

To upgrade licensed internal code fixes on your managed systems for a current release click “upgrade licensed internal code for the current release”

HMC Security: Servers and Clients communicate over the secure sockets layer(SSL). Which provides server authentication, data encryption and data integration.

HMC Serial number lshmc -v

To format the DVD-RAM media

The following steps show how to format the DVD-RAM disk:

1. Place a DVD-RAM disk in to the HMC DVD drive.

2. In the HMC Navigation area,under your managed system, click Licensed Internal Code


3. Then click HMC Code Update.

4. In the right-hand window, click Format Removable Media.

5. Then select the Format DVD radio button.

6. Select Backup/restore.

7. Then click the Format button.

The DVD-RAM disk should be formatted in a few seconds, after which you will receive a

“Format DVD has been successfully completed - ACT0001F” message.

Back up to formatted DVD media

Use the following steps to back up the CCD to the formatted DVD media:

1. In the HMC Navigation area, click Licensed Internal Code Maintenance.

2. Then click the HMC Code Update.

3. In the right-hand window, click Back up Critical Console Data.

4. Select the Back up to DVD on local system radio button and click the Next button.

5. Enter some valid text in the description window and click OK.

1 comment:

  1. sir really gr8. got lot of concepts related to lpar.