Resources of not activated LPARs

When an LPAR is shutdown, resources such as processors, memory, and I/O slots are not automatically released by the LPAR. The resources remain assigned to the LPAR and are reused on the next activation (with the current configuration).

The article will show how such resources are automatically released and, if desired, how to manually release resources of an inactive LPAR.

(Note: In the example output, we use version 1.4 of the LPAR tool, but in all cases we show the underlying commands on the HMC command line, so you can try everything without using the LPAR tool.)

The example LPAR lpar1 was shut down, but currently still occupies 100 GB of memory:

linux $ lpar status lpar1
NAME   LPAR_ID  LPAR_ENV  STATE          PROFILE   SYNC  RMC       PROCS  PROC_UNITS  MEM     OS_VERSION
lpar1  39       aixlinux  Not Activated  standard  0     inactive  1      0.2         102400  Unknown
linux $

The following commands for the output above were executed on the corresponding HMC hmc01:

hmc01: lssyscfg -r lpar -m ms09 --filter lpar_names=lpar1
hmc01: lshwres -r mem -m ms09 --level lpar --filter lpar_names=lpar1
hmc01: lshwres -r proc -m ms09 --level lpar --filter lpar_names=lpar1

The resource_config attribute of an LPAR indicates whether the LPAR has currently allocated resources (resource_config=1) or not (resource_config=0):

linux $ lpar status -F resource_config lpar1
1
linux $

Or on the HMC command line:

hmc01: lssyscfg -r lpar -m ms09 --filter lpar_names=lpar1 –F resource_config

The resources allocated by an not activated LPAR can be released in 2 different ways:

  1. Automatic: The resources used are needed by another LPAR, e.g. because memory is expanded dynamically or an LPAR is activated that does not have sufficient resources. In this case, resources are automatically removed from a not activated LPAR. We will show this below with an example.
  2. Manual: The allocated resources are explicitly released by the administrator. This is also shown below in an example.

First we show an example in which resources are automatically taken away from an not activated LPAR.

The managed system ms09 currently has about 36 GB free memory:

linux $ ms lsmem ms09
NAME  INSTALLED  FIRMWARE  CONFIGURABLE  AVAIL  MEM_REGION_SIZE
ms09  786432     33792     786432        36352  256
linux $

HMC command line:

hmc01: lshwres -r mem -m ms09 --level sys

We start an LPAR (lpar2) which was configured with 100 GB of RAM. The managed system has only 36 GB of RAM and is therefore forced to take resources from inactive LPARs in order to provide the required 100 GB. We start lpar2 with the profile standard and look at the memory relations:

linux $ lpar activate -b sms -p standard lpar2
linux $

HMC command line:

hmc01: chsysstate -m ms09 -r lpar -o on -n lpar2 -b sms -f standard

Overview of the storage relations of lpar1 and lpar2:

linux $ lpar status lpar\*
NAME   LPAR_ID  LPAR_ENV  STATE          PROFILE   SYNC  RMC       PROCS  PROC_UNITS  MEM     OS_VERSION
lpar1  4        aixlinux  Not Activated  standard  0     inactive  1      0.2         60160   Unknown
lpar2  8        aixlinux  Open Firmware  standard  0     inactive  1      0.2         102400  Unknown
linux $ ms lsmem ms09
NAME  INSTALLED  FIRMWARE  CONFIGURABLE  AVAIL  MEM_REGION_SIZE
ms09  786432     35584     786432        0      256
linux $

HMC command line:

hmc01: lssyscfg -r lpar -m ms09
hmc01: lshwres -r mem -m ms09 --level lpar
hmc01: lshwres -r proc -m ms09 --level lpar
hmc01: lshwres -r mem -m ms09 --level sys

The LPAR lpar2 has 100 GB RAM, the managed system has no more free memory and the memory allocated by LPAR lpar1 has been reduced to about 60 GB. Allocated resources from non-activated LPARs are automatically released, when needed and assigned to other LPARs.

But you can of course also release the resources manually. This is also shown briefly here. We are reducing the memory of LPAR lpar1 by 20 GB:

linux $ lpar -d rmmem lpar1 20480
linux $

HMC command line:

hmc01: chhwres -m ms09 -r mem  -o r -p lpar1 -q 20480

As stated, the allocated memory has been reduced by 20 GB:

linux $ lpar status lpar\*
NAME   LPAR_ID  LPAR_ENV  STATE          PROFILE   SYNC  RMC       PROCS  PROC_UNITS  MEM     OS_VERSION
lpar1  4        aixlinux  Not Activated  standard  0     inactive  1      0.2         39680   Unknown
lpar2  8        aixlinux  Open Firmware  standard  0     inactive  1      0.2         102400  Unknown
linux $ ms lsmem ms09
NAME  INSTALLED  FIRMWARE  CONFIGURABLE  AVAIL  MEM_REGION_SIZE
ms09  786432     35584     786432        20480  256
linux $

HMC command line:

hmc01: lssyscfg -r lpar -m ms09
hmc01: lshwres -r mem -m ms09 --level lpar
hmc01: lshwres -r proc -m ms09 --level lpar
hmc01: lshwres -r mem -m ms09 --level sys

The 20 GB are immediately available to the managed system as free memory. If you remove the entire memory or all processors (or processor units), then all resources of an inactive LPAR are released:

linux $ lpar -d rmmem lpar1 39680
linux $

HMC command line:

hmc01: chhwres -m ms09 -r mem  -o r -p lpar1 -q 39680

Here are the resulting memory relations:

linux $ lpar status lpar\*
NAME   LPAR_ID  LPAR_ENV  STATE          PROFILE   SYNC  RMC       PROCS  PROC_UNITS  MEM     OS_VERSION
lpar1  4        aixlinux  Not Activated  standard  0     inactive  0      0.0         0       Unknown
lpar2  8        aixlinux  Open Firmware  standard  0     inactive  1      0.2         102400  Unknown
linux $ ms lsmem ms09
NAME        INSTALLED  FIRMWARE  CONFIGURABLE  AVAIL  MEM_REGION_SIZE
ms09  786432     31232     786432        64512  256
linux $

HMC command line:

hmc01: lssyscfg -r lpar -m ms09
hmc01: lshwres -r mem -m ms09 --level lpar
hmc01: lshwres -r proc -m ms09 --level lpar
hmc01: lshwres -r mem -m ms09 --level sys

The LPAR lpar1 now has 0 processors, 0.0 processor units and 0 MB of memory! In addition, the resource_config attribute now has the value 0, which indicates that the LPAR no longer has any resources configured!

linux $ lpar status -F resource_config lpar1
0
linux $

HMC command line:

hmc01: lssyscfg -r lpar -m ms09 --filter lpar_names=lpar1 –F resource_config

Finally, the question arises as to why you should release resources manually if they are automatically released by the managed system when needed?

We will answer this question in a second article.