The Partition Load Manager (PLM) provides CPU and memory resource management and monitoring across logical partitions (LPARs). Partition Load Manager allows you to effectively use CPU and Memory resources by allowing you to set thresholds for designated resources. When a threshold is exceeded, Partition Load Manager can try to assign CPU and/or Memory resources to that LPAR by using resources assigned to other LPARs that are not being used.

PLM is an automated mechanism for utilizing the Dynamic LPAR (DLPAR) capabilities of the HMC and requires communication with the HMC. This means that before PLM will function, DLPAR must be functional on the HMC. DLPAR requires communication with each LPAR via the Resource Monitoring and Control (RMC) subsystem.

Preparation for implementation of PLM

Install and configure SSL and OpenSSH.

Verify or install the following fileset on the PLM Server and every PLM client LPAR::

• csm.client

After installation of the "csm.client" file, run the following commands to initialize the RMC subsystem:

cd /usr/sbin/rsct/install/bin
./recfgct
lssrc -a | grep rsct

From the above "lssrc" output, check to ensure "IBM.CSMAgentRM" is running. Repeat these steps on every PLM client LPAR.

Before implementing this rest of this procedure, verify the HMC is able to perform DLPAR functions to the client LPAR, then continue. If the HMC is unable to perform a DLPAR, PLM will not work.

Implementing PLM

Install the following filesets:

• plm.license
• plm.server.rte
• plm.sysmgt.websm

For setup of PLM, create .rhosts files on the server and all clients. After PLM has been set up, you can delete the .rhosts files.

Create SSH keys

On the PLM server, enter:

ssh-keygen -t rsa

Copy the HMC "authorized keys" file to the PLM server

HMCHOSTNAME="<enter the HMC host name here>"
PLMSERVERHOSTNAME="<enter the PLM Server host name here>"
scp hscroot@${HMCHOSTNAME}:.ssh/authorized_keys2 ~/.ssh/tmp_authorized_keys2

Append the PLM server keys to the temporary HMC "authorized keys" file and copy it back to the HMC:

cat ~/.ssh/id_rsa.pub >> ~/.ssh/tmp_authorized_keys2
scp ~/.ssh/tmp_authorized_keys2 hscroot@${HMCHOSTNAME}:.ssh/authorized_keys2

Test SSH and enable WebSM

Test SSH to the HMC. You should not be asked for a password.

ssh hscroot@${HMCHOSTNAME} lssyscfg -r sys

On the PLM server, make sure you can run WebSM:

/usr/websm/bin/wsmserver -enable

Configure the PLM Server

On the PLM server, open WebSM and select Partition Load Manager.

Click on ghe Globals tab and enter the fully qualified hostname of your HMC. Enter "hscroot" as the HMC user name. Enter the CEC name, which can be obtained by running the following command on the PLM server:

ssh hscroot@${HMCHOSTNAME} lssyscfg -sys -F name

Select the system name that corresponds to the frame you are configuring in the PLM server and enter this as the CEC name.

Click on the Groups tab and add the groups "dedicated" and "shared". The maximum values should be the total amount of CPU and memory on the frame being configured to be managed by the PLM. Click on CPU and memory management to manage both.

Click on the partitions tab and add all the LPAR's on the frame to be managed by the PLM. Use the fully qualified domain name as the partition name for each LPAR.

Click on OK to create the policy file and verify it's existance on the PLM server under "/etc/plm/policies"

From the WebSM interface of the PLM, perform the PLM setup. NOTE: You must be logged into the PLM server through the WebSM interface as "root" to perform this step.

Test RMC Authentication

Test RMC authentication by running the following command from the PLM server, where "plm_client_name" is the hostname of the LPAR that will be managed by PLM.

CT_CONTACT=plm_client_name  lsrsrc  IBM.LPAR

If successful, several lines of LPAR information will be printed out instead of "Could not authenticate user".

Start the PLM Server

From the WebSM interface of the PLM server, start the PLM server. Enter the full path file name of the policy file name. The full path file name of the policy file will be the directory "/etc/plm/policies" followed by the serial number of the frame. Any alphabetic characters in the serial number must be entered in UPPERCASE letters. For example:

/etc/plm/policies/10F6BEE

/var/opt/plm/10F6BEE.log

NOTE: You may have to "touch" the logfile before starting the PLM Server

Troubleshooting

If the PLM server does not start, check the PLM server file "/var/ct/cfg/ctrmc.acls" to ensure the following lines are at the bottom of the file:

IBM.LPAR
	root@${HMCHOSTNAME}	*	rw

NOTE: Even though there is no access to the "root" user on the HMC, this line should still reference "root@${HMCHOSTNAME}", where ${HMCHOSTNAME} is replaced by the actual HMC Hostname.

On the PLM client LPAR check the same file "/var/ct/cfg/ctrmc.acls" to ensure the following lines are at the bottom of the file. Recognize the last line of this file on a PLM client LPAR will reference the PLM Server hostname rather than the HMC hostname:

IBM.LPAR
	root@${PLMSERVERHOSTNAME}	*	rw

NOTE: this line should reference "root@${PLMSERVERHOSTNAME}", where ${PLMSERVERHOSTNAME} is replaced by the actual server hostname where PLM resides.

If you edit, the "/var/ct/cfg/cgrmc.acls" file on the PLM server or on a PLM client LPAR, restart the RMC subsystem on the modified systems.

refresh -s ctrmc

Troubleshooting

If the PLM server still does not start, there is most likely an RMC authentication problem. Begin by obtaining a list of trusted hosts by running the following command on the PLM server:

/usr/sbin/rsct/bin/ctsvhbal

One or more identities of the PLM client LPAR should appear in this list. If not you may need to rerun the PLM Setup. This can be performed from the WebSM interface or from the command line on the PLM server. The command line is:

cd /etc/plm/setup
PLMCLIENT="<Fully qualified PLM Client Host Name>"
./plmsetup  ${PLMCLIENT}  root

On the PLM client LPAR check the list of trusted hosts by running the following command:

/usr/sbin/rsct/bin/ctsthl -l

The PLM Server host name should appear in this list. If multiple identities exist, it is usually a good idea to remove them all and rerun the PLM setup command on the PLM server. To remove the trusted host identities on a PLM client LPAR, run the following command:

/usr/sbin/rsct/bin/ctsthl -d -n <hostname>

Trusted host identities can be added on the PLM server or client LPAR's using the following command:

/usr/sbin/rsct/bin/ctsthl -a -n <hostname> -m rsa512 -p <identifier>

Where the <identifier> can be obtained by running ctsthl -l on the opposite system to determine it's value.

Troubleshooting

One problem that was encountered with the PLM server was when using the WebSM interface and clicking on the link labeled "Show LPAR Statistics", a dialog window would appear filled with java errors, and the statistics screen would not start. This was apparently due to a formatting problem with the policy file itself. However the PLM server will start and there are no obvious errors other than the inability to click on the "Show LPAR Statistics" link.

The fix for this problem is to delete the Policy file and create a new one.