Mt Xia: Business Continuity/Disaster Recovery Methodologies
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::
After installation of the "csm.client" file, run the following commands to initialize the RMC subsystem:
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.
Install the following filesets:
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:
Copy the HMC secure keys to the PLM server
Append the PLM server keys to the temporary key file and copy it back to the HMC:
Test SSH and enable WebSM
Test SSH to the HMC. You should not be asked for a password.
On the PLM server, make sure you can run WebSM:
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:
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.
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:
Also enter the full path file name of a log file where the PLM will store activity information. Several utilities are dependent upon the information contained within the log file so it is important that this log file be created in the correct directory with the correct name. The log file directory is "/var/opt/plm" and the log file name is the serial number of the frame followed by ".log". Any alphabetic characters in the serial number must be entered in UPPERCASE letters. For example:
NOTE: You may have to "touch" the logfile before starting the PLM Server
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:
NOTE: Even though there is no access to the "root" user on the HMC, this line should still reference "root@hmcHostname".
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:
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.
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:
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:
On the PLM client LPAR check the list of trusted hosts by running the following command:
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:
Trusted host identities can be added on the PLM server or client LPAR's using the following command:
Where the <identifier> can be obtained by running ctsthl -l on the opposite system to determine it's value.
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.
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