System z: Checklist for Establishing Group Capacity Profiles

Transcription

1 System z: Checklist for Establishing Group Capacity Profiles This document can be found on the web, ATS Author: Pedro Acosta Consulting IT Specialist Co-Author: Toni Skrajnar Senior RTSC Software Specialist

2 Trademarks The following terms are registered trademarks of International Business Machines Corporation in the United States and/or other countries: BladeCenter, CICS, DataPower, DB2, e business(logo), ESCON, eserver, FICON, IBM, IBM (logo), IMS, MVS, OS/390, POWER6, POWER6+, POWER7, Power Architecture, PowerVM, PureFlex, PureSystems, S/390, ServerProven, Sysplex Timer, System p, System p5, System x, System z, System z9, System z10, WebSphere, X- Architecture, z9, z10, z/architecture, z/os, z/vm, z/vse, zenterprise, zseries The following terms are trademarks of International Business Machines Corporation in the United States and/or other countries: DB2 Universal Database, DEEP BLUE, e-business (logo), ~, GigaProcessor, HACMP/6000, Intelligent Miner, iseries, Network Station, NUMACenter, POWER2 Architecture, PowerPC 604,pSeries, Sequent (logo), SmoothStart, SP, System z, xseries, zseries. For a more complete list of IBM trademarks visit: NetView, Tivoli and TME are registered trademarks and TME Enterprise is a trademark of Tivoli Systems, Inc. in the United States and/or other countries. Oracle, MetaLink are registered trademarks of Oracle Corporation in the USA and/or other countries. Microsoft, Windows, Windows NT and the Windows logo are registered trademarks of Microsoft Corporation in the United States and/or other countries. UNIX is a registered trademark in the United States and other countries licensed exclusively through The Open Group. LINUX is a registered trademark of Linus Torvalds. Intel and Pentium are registered trademarks and MMX, Pentium II Xeon and Pentium III Xeon are trademarks of Intel Corporation in the United States and/or other countries. Java and all Java-based trademarks and logos are trademarks of Sun Microsystems, Inc. in the United States and/or other countries. Other company, product and service names may be trademarks or service marks of others.

3 Table of Contents Introduction... 4 Step 1: Verify that initial capping (hard capping) is turned off... 5 Step 2: Creating Group Capacity Profiles... 7 Step 3: Adding member LPARs to Group Profile... 9 Step 4: Verify Group Capacity profile has been activated Note about Enhanced SMF recording Summary Appendix A Finding Operational Customization Menu on HMC Tree View Page 3 of 15

4 Introduction Group Capacity enables the management of capacity for multiple z/os LPARs on a single CEC (central electronic complex) to a specified MSU (Million service units) limit allowing better management of CPU usage. The Group Capacity feature is available to all LPARs running z/os V1R8 or higher. WLM on z/os allows management of an LPAR to a specified Defined Capacity, or soft cap for LPARs using shared CPs. This value allows an LPAR to be capped when the LPAR s capacity exceeds the set limit as judged by a rolling 4-hour average. WLM and PR/SM may apply a processor cap to ensure the capacity does not, on average, exceed the Defined Capacity. As the demand for CPU is reduced, and subsequently the rolling 4- hour average no longer exceeds the defined capacity, the soft capping function will be removed dynamically by WLM and PR/SM. Defined Capacity cannot be defined for a partition that has an Initial Capping (hard cap) on GCPs. A Group Capacity limit is similar to Defined Capacity, except it defines the software MSU limit for a group of LPARs. Capacity groups are defined at the HMC with a capacity limit in MSUs for all the members of the group. Each LPAR may be defined to only one group. As LPARs in the group run work, their rolling 4-hour average is calculated. If the total rolling 4-hour average for the group reaches the group capacity limit, each LPAR is then capped to its target limit. The target limit assigned to each LPAR is based on its LPAR weight as a percentage of the sum of the weights of all member LPARs. This paper describes the procedure for setting up a Group Capacity profile and assigning LPARs to become members of the group. Page 4 of 15

5 When you logon to the HMC you will be taken to either the Classic view or the new Tree view. These instructions will be using the Classic view. The process is very similar for the Tree view, with a few exceptions, which are covered in Appendix A. Step 1: Verify that initial capping (hard capping) is turned off In order for the group capacity to take effect on your system you must first turn off initial capping for the LPARs you will assign to the Group Capacity profile. The following instructions will guide this process: In the top Views section, select Groups (1) In the Groups Work Area section below, select Defined CPCs (2) This will show the Defined CPCs Work Area Section. Select the desired CPC (3) Navigate to the Operational Customization by using the navigation arrows on the lower right hand side of the screen and select Change LPAR Controls. Page 5 of 15

6 Verify that the Initial Capping box is unchecked for the LPARs you wish to assign to the Group Capacity profile. Save these changes or apply to the system by making one of the following selections: (1) Save to Profiles Saves LPAR profiles only Note: This is not an option if you plan on dynamically making the changes to the LPARs. (2) Change Running System Dynamically apply the changes to all running partitions. Changes are lost after a Power-On Reset is performed. (3) Save and Change - Saves LPAR profiles and make changes to the running system. Selecting this option will ensure the changes remain in effect even after performing a Power-On Reset. By selecting Save and Change you have now modified the Initial Capping profile for the desired LPARs and have dynamically changed the running system. These changes will remain even after a Power-On Reset is performed on the CEC. Page 6 of 15

7 Step 2: Creating Group Capacity Profiles Now that we have verified that Initial Capping is not active for the LPARs that will be part of the group, let s create a new Group Capacity profile: On the Operational Customization panel, select Customize/Delete Activation Profiles. On the list, uncheck the default Reset profile checkbox named DEFAULT. Page 7 of 15

8 On the list you will see a Group profile also called DEFAULT. Check this profile and then click Customize Profile at the bottom of the window. On the next screen, overtype the group named DEFAULT with your new group name. In this example Group1 is used. Change the group description to a description of your choice and input the desired Group capacity value in MSUs. Click the Save button at the bottom of the window. Another window will appear asking to continue with the save; click OK to complete this process. 1 2 You have now defined your Group Capacity Profile, called here Group1, and it should be visible in Customize/Delete Activation Profiles. You may repeat this process when defining new Group Profiles or making changes to existing ones. Page 8 of 15

9 Close the Customize/Delete Activation Profiles window by selecting Close at the bottom of the screen. Step 3: Adding member LPARs to Group Profile Let s now add some LPARs to the newly created group. You should now be back on the Defined CPCs Work Area; select the desired CPC Under Operational Customization, select Change LPAR Group Controls You should now see the group profile you created. Select the Edit pull down menu then select Edit Group Members. Page 9 of 15

10 Assign the desired partitions to your new group by typing the name of the group in the corresponding text box. In this example we are adding three LPARs to Group1: TOSP1, TOSP2, and TOSP3. Click OK when done assignment of LPARs to the group. You should now be back on the Change LPAR Group Controls window and you should now see, under the column titled Member Partitions, the LPAR names for the corresponding group(s). Now we have to make the changes permanent. We have three choices to accomplish this: (1) Save to Profiles Saves the profile definitions but DOES NOT activate the Group Capacity Note: This option will only assign partitions to a group if the partition is currently inactive. Active partitions will be added to the group next time these partitions are reactivated. This option is not recommended if you want the effect to take place immediately. 15 Page 10 of

11 (2) Change Running System Dynamically implements the change to the system, however, changes will be lost if a Power-On Reset on the CEC is performed. (3) Save and Change Saves the changes to the profile definition AND activates the group capacity profile, including adding currently active partitions. By selecting Save and Change you have now assigned LPARs to the group and have dynamically changed the running system. These changes will remain even after a PowerOn Reset is performed on the CEC. After a brief moment you will get a confirmation window displaying the status of the change made to the Running System. Selecting OK closes the window. The LRAPs should now be identified as part of the group. The next step will guide you in verifying the group capacity profile has been activated. 15 Page 11 of

12 Step 4: Verify Group Capacity profile has been activated If you dynamically activated the changes to add a capacity group you can verify it worked using RMF reports. You can use an online monitor such as RMF Monitor III to see if the LPAR now has an active cap. In RMF Monitor III use the CPC Capacity panel to verify the changes. If the LPAR has been made part of a Group Capacity this is indicated on the top right hand corner of the screen by the Group Name and Limit as depicted here: Note about Enhanced SMF recording Now that you have created and activated your Group Capacity profile, it is recommended that you turn on recording of SMF 99 subtype 11. If a problem should arise the SMF 99 subtype 11 records would be required to do problem determination. Therefore, it is recommended the data be collected unconditionally. Some information about this data: The collected data is small and only written every 5 minutes Size is about 1300 bytes fixed bytes per LPAR on a CEC (Approximately 3k for a CEC with 8 partitions) 15 Page 12 of

13 Summary Group Capacity profiles are specified via LPAR definitions on the HMC. These profiles allow the management of CPU for a group of z/os LPARs on a single CEC. It provides sub-cec capacity by allowing definition of LPAR capacity in MSUs with granularity of 1 MSU. In order for group capacity to take effect, Initial Capping (or hard cap) cannot be defined for the same partition. Limits are determined by using WLM s rolling 4-hour average in MSUs. RMF records are then used to verify and monitor the effect of group capacity profiles. Lastly, it is recommended that monitoring of SMF 99 subtype 11 records be turned-on for systems in which group capacity profiles are implemented. 15 Page 13 of

14 Appendix A Finding Operational Customization Menu on HMC Tree View On the left hand side navigation pane Click to expand Systems Management Click to expand Systems Click to highlight the CPC in question The body of the screen will now show the tasks related to that CPC. Click to expand Operational Customization Proceed creating the Group Profile and adding new partitions to the group by following the instructions discussed in Steps 1 through 4 of this guide. 15 Page 14 of

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