PM for Power Systems

IBM i operating system

Are you looking for AIX FAQ?

• Reports FAQ (AIX)

What is the Management Summary Graph? 
Please refer to:

• Management Summary Graph (5.75MB)

Who can I contact for pricing or additional information? 
Please refer to:

• Country Pricing and Contact Information

Why are the guidelines used for PM for Power Systems different from those in the Work Management Manual? 
The guidelines for good performance in the Work Management Manual are based on instantaneous measurements whereas those used for PM for Power Systems are monthly averages. It follows therefore that if a resource averages; say 50% over a period, then there will be times when the utilization will be both significantly higher and lower in order to achieve that average. During the times when the utilization is higher, the customer may experience lesser performance degradation than if the utilization was consistently 50%.

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What are the guideline values for warning (yellow) and critical (red) CPU resource utilization? 
These values vary depending on the number of processors on the system or allocated to a logical partition on an LPAR system and are based on the guidelines for good performance and standard queuing models for n-way processors.

CPU: System + Interactive Utilization

Number of Processors	Average Marginal	Average Critical	Peak Marginal	Peak Critical
1	45%	60%	56%	70%
2	60%	75%	72%	83%
3	67%	81%	80%	88%
4	71%	85%	81%	91%
>4	75%	90%	86%	94%

CPU: Total System Utilization

Number of Processors	Average Marginal	Average Critical	Peak Marginal	Peak Critical
1	80%	90%	85%	94%
2	85%	93%	88%	96%
3	87%	94%	90%	97%
4	89%	95%	92%	98%
>4	93%	97%	95%	99%

CPU: Interactive Feature Utilization

Average Marginal	Average Critical	Peak Marginal	Peak Critical
80%	100%	80%	100%

Disk Space

Marginal	Critical
70%	80%

As always, these are guidelines. The actual performance experienced by a customer may be quite satisfactory at a utilization in excess of these guidelines and equally, it may prove unacceptable before these guidelines are reached.

Note also, for processors with Interactive feature codes the lower value of "System + Interactive" percentage of the total system CPW or the CPW capacity of the Interactive Feature(s) should be used as the guideline for both the Average, Peak Marginal and Critical percentages.

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How do I interpret PM for Power Systems reports in an LPAR environment? 
PM for Power Systems Logical Partitioning (LPAR) Considerations
PM for Power Systems has limited support for the implementation of LPAR in customer using OS/400 Version 4 Release 5, Version 5 Release 1 or Version 5 Release 2. The performance data collected is based on each individual partition which transmits, so any reports produced can only reflect the performance and utilization characteristics of the partition involved. There is no facility available to provide a "rolled up" view of the entire system.

Please Note: If you are using only one partition (no LPAR) all information is reported accurately.

Important: Machines that have LPAR implemented must collect performance data using Collection Services for accurate LPAR reporting.

Processor Assignment
LPAR allows the number of processors assigned to a partition to be changed and therefore it must be recognized that if this is done during the reporting period, either across the month or during the days of that month, any predictions will be based on that profile being consistent across the following days and months. This may not always be the case.

Interactive Feature Card(s)
On a system which has implemented LPAR the interactive processing capacity is allocated across the partitions on a percentage basis. The Executive Summary Graph (150) and Management Summary Graphs (175) will show the utilization percentage of the amount of the Interactive Capacity assigned to that partition and will base their predictions of the Months to Guideline on the same criteria. The same consideration about the processor allocation profile as mentioned above applies.

Disk Allocation
Just as the number of processors and percentage of the interactive feature cards allocated to a partition can be readily changed, it is also possible to change the amount of disk allocated. Trend calculations for disk utilization are based on the disk storage profile remaining constant and this must be considered when evaluating the relevant reports.

Total System View
PM for Power Systems cannot present a "rolled up" view of the total system. This is because some of the underlying measurements are not present. For example, on these releases there is no cross-reference to the primary system time to allow the offsetting of performance data from the other partitions which is a fundamental requirement to present such a consolidation.

Total System Implications that can be inferred from PM for Power Systems data reported by Partition: What is possible today? There are some conclusions which can be drawn from the PM for Power Systems performance data but this is not automatically consolidated. It is necessary to include two caveats here:

• Unless all partitions are reporting their performance data, no conclusions can be drawn about the total system.
• Unless all partitions are operating with their system clocks set to the same time as the processor, utilization becomes much more difficult to analyze and the offset calculation must be performed manually.

DASD Reports:
As these present a view of the average amount of DASD space used in each partition during the reporting period the time displacement is of little consequence. All partitions will almost certainly have a different amount of DASD assigned to them so it is not legitimate to simply average the utilization show for each partition. What must be done is to convert the utilization percentages to "used" and "available" Gigabytes or Megabytes for each partition and then sum these values. This will then show the percentage of the total system's DASD is being used. For example:

Partition Number	Total DASD (MB)	PM for Power Systems Percentage Used	Amount Used (MB)
1	80,000	50%	40,000
2	50,000	80%	40,000
3	30,000	40%	12,000
4	70,000	60%	42,000
Total	230,000		134,000

The PM for Power Systems reports for each partition will show you if a particular partition is DASD constrained and this simple table will indicate if your system is constrained or not. This particular example shows although your total system's DASD is only slightly over 58% utilized (134,000/230,000), partition 2 is approaching a critical situation while the other partitions appear to have space to spare. Subject to granularity considerations it might be appropriate to reassign DASD from part partitions 1, 3 or 4. In this case, moving say 10,000 MB from partition 4 to partition 2 would result in utilization values of approximately 71% and 68% respectively. However, factors such as disk arm utilization and granularity of DASD devices must also be considered.

Processor Reports:
Analysis of these is much more difficult, particularly when there is a real time offset between partitions. On the assumption all partitions have identical date and times on their system clocks then it is possible to calculate a weighted average from looking at the same reports for all partitions. For example:

Partition Number	Number of Processors	Number of Transactions	Average Response Time	Total Resource (see note)
1	4	3,000	0.50 seconds	1,500
2	2	5,000	0.75 seconds	3,750
3	4	8,000	1.5 seconds	2,800
4	2	2,000	1.5 seconds	3,000
Total	12	18,000		11,050

Note: This is not a 100% accurate reflection of what resource is being used but it may prove a useful approximation.

We can therefore say the average response time across all partitions is 0.614 seconds (11,050/18,000). If it were desired to improve the response time for partition 4 then moving a processor from partition 1 or 3 may have the desired effect (a processor upgrade might also be appropriate). However, in most cases where LPAR is implemented the reason processors are allocated to particular partitions is to optimize response time for the users of that partition. To properly understand what is going on in each partition it is probably desirable to utilize one of the more sophisticated performance analysis tools.

If the system date and time across partitions differs, then the calculations become much more complex as the same weighting must be done for each time period across the reporting day and/or month and allowance must be made for the appropriate offset.

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What are some common report problems? 
Common problems with reports.

1. Missing or incorrect mailing address information.
   • To change, modify, or correct your mailing address information or company title on reports use GO PM400 or GO QMPGLIB/PM400 , and then choose 'Work with Contact Information' option.
2. To determine 1st and 2nd shift for reports.
   • The shift windows can be viewed or changed with GO PM400 or GO QMPGLIB/PM400, and then choose 'Work with PM for System i Customization' option.
3. Peaks over 100 utilization on the CPU

   • Peaks over 100 utilization on the CPU Utilization graphic pages or on the Management Summary page of the reports can be caused by running a backup during the data reduction. Data reduction refers to the process of compressing the large amount of raw performance monitor data into the PM for Power Systems files, by default data reduction is run at midnight.

      

     If you notice this problem move the time of data reduction job to 11:30pm.

     To change the time of any PM for Power Systems scheduled job:

     1. On the System i command line type GO QMPGLIB/PM400.
     2. Take 'Work with Automatically Scheduled Jobs' option from the PM for Power Systems main menu.
     3. Use option 2 on the Q1PDR job.
     4. Key in 23:00 for 11:00PM.

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I'm trying to view my PM for Power Systems Reports with Internet Explorer and I get the following error: "No viewer available for the type of object you are trying to open". What should I do? 
This condition can arise with an out of date or corrupt Adobe reader file. For no charge updates, installations, or to re-install, please go to the Adobe Web site:

Get Adobe® Reader®

The utilization percentage shown on the Management Summary Graph for "Processor, Interactive" is higher than that shown for "Processor, System + Interactive". How can this be? 
They are expressed as percentages of different guidelines. The "Processor, Interactive + System" is calculated as a percentage of the system's total processing capacity while that for the "Processor Interactive" is expressed as a percentage of the system's Interactive Processing Capability.

The reason this is done is to identify when it is necessary to take action to increase the system's Interactive Capacity. As some systems have implemented Feature Cards to provide the Interactive Capacity it would be possible for the "System + Interactive" utilization to be below the guideline but for there to be inadequate Interactive Feature Card capacity on the system.

The "Processor, Interactive" report uses the lower of the guideline based on the Interactive Feature Cards or the guideline based on the "Number of Processors" queuing algorithm. The guideline values on which these two reports are based are shown on the Facts pull down of report 675 "Processor Trend, Interactive". The system's Interactive Card Feature is shown on this graph as a horizontal red line which can be either below or above the guideline based on the number of processors.

I have just activated the PM Agent. When will I receive my userid and registration key/password? 
The registration letter that contains your userid and registration key/password providing access to your online reports will be sent within one business day of receipt of your PM for Power Systems data.

Why is my company name incomplete on every page of the report? 
The company name field holds approximately 32 mixed case characters. Upper case letters take up more room than lower case letters. To change go to the PM Agent main menu by typing GO PM400 on the System i command line. Take the Work with Contact Information option. Shorten the company name or change some characters from upper to lower case to take up less space on the report.

Is there a Memory Faulting Graph Available? 
Yes, as of March 2002, a graph was developed to represent a new approach to evaluating the "effect" of page faulting. Instead of simply using the number of faults as being good or bad, the graph depicts the "cost" of the faults as the measure of good or bad. The 'cost' of a fault is the time for the disk operation (read) to complete. The 'cost' can vary depending on the arm utilization at the time of the fault.

The result is expressed as a 'percentage' of time spent faulting vs. time spent in the application.
OS/400 Version 5 Release 1 with PTF # SI02447 is a prerequisite to the availability of this graph.

To see an example of the new memory graph:

• Memory Graph (5.75MB)

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