amepat Command
Purpose
Active Memory Expansion Planning and Advisory Tool amepat reports Active Memory Expansion (AME) information and statistics as well as provides advisory report that assists in planning the use of Active Memory Expansion for an existing workload.
Syntax
amepat [{{[-c max_ame_cpuusage% ] | [-C max_ame_cpuusage ]}|[ -e startexpfactor [ :stopexpfactor [ :incexpfactor ] ]]}][{[ -t tgt_expmem_size]|[ -a ]}]
[ -n num_entries ] [-m min_mem_gain ] [-u minucomp_poolsize ]
[-v ] [-M] [ -N ] [-O proc=<processor implementation> ][{ [ -P recfile ] | [ Duration ] | [ Interval <Samples> ]}]
amepat [ -N ] [ -R recfile ] {[ Duration] | [ Interval <Samples>]}
Description
- Workload Planning - The amepat can be run to determine a workload that would benefit from Active Memory Expansion, and also to provide a list of possible Active Memory Expansion configurations for a workload.
- Monitoring - When Active Memory Expansion is enabled, the amepat tool can be used to monitor the workload and Active Memory Expansion performance statistics.
- In the Recording mode amepat records systems configuration and various performance statistics into a user specified recording file.
- In the Reporting mode amepat analyzes the system configuration and performance statistics, collected in real time or from the user specified recording file, to generate workload utilization and planning reports.
Workload Planning
When considering using Active Memory Expansion for an existing workload, amepat can be used to provide guidance on possible Active Memory Expansion configurations for the workload. When amepat is run concurrently with an existing workload that is not using Active Memory Expansion, amepat monitors the memory usage, memory reference patterns, and data compressibility over a user-configurable time period of the workload. The tool then generate a report with a list of possible Active Memory Expansion configurations for the workload. The tool includes an estimate of the processor utilization impacts for the different Active Memory Expansion configurations.
The amepat command can be run on all versions of IBM® Power Systems servers supported by AIX 6.1, and later.
There are two key considerations when running amepat to do workload planning: the time at which to run the tool and the duration to run the tool. To get the best possible results from the tool, the tool must be run during the period of peak utilization of the workload. It ensures that the tool captures peak of utilization and memory usage information of the workload.
To use amepat to generate a report for workload planning, a monitoring duration must be specified when starting amepat.
In addition to using amepat on workload that are not yet using Active Memory Expansion, amepat can also be run in LPAR’s where Active Memory Expansion is already enabled. When used in this mode, amepat it provides a report of other possible Active Memory Expansion configurations for the workload.
Monitoring
amepat can also be used to monitor the processor and memory utilization statistics (Disabling the workload planning capability). With this Monitoring capability, amepat just gathers processor and memory utilization statistics, does not gather the additional data required for generating the report for workload planning. Thus, Active Memory Expansion Modeling and Advisory reports are not generated.
When amepat is started without a duration or interval, amepat defaults to monitoring only capability, and amepat reports a snapshot of the LPAR’s memory, processor utilization.
amepat can be started with duration and run with Monitoring only capability using the -N flag. The -N flag disables the workload planning capability of this tool, thus disabling the data gathering process & reporting for workload planning.
amepat Report
Following are the six different sections of report displayed by the amepat tool:
Command Information Section
The Command Information Section provides details about the arguments passed to the amepat tool, time of invocation, the total time the system is monitored and the number of samples collected.
System Configuration Section
The System Configuration Section provides details about the system configuration. The following table provides the complete list of information reported.
Item | Description |
---|---|
Partition Name | Node name from where amepat is started |
Processor Implementation Mode | The processor implementation mode. It can be POWER4, POWER5, POWER6®, and so on. |
Number Of Logical CPUs | The total number of logical processors configured and active in the partition. |
Processor Entitled Capacity | Capacity Entitlement of the partition, represented
in the unit of number of physical processors. Note: The physical processor
units can be in fraction as well, for example, 0.5 physical processor.
|
Processor Max. Capacity | Maximum Capacity this partition can have, represented
in the unit of number of physical processors Note: The physical processor
units can be in fraction as well, for example, 0.5 physical processor.
|
True Memory | The true memory represents real physical or logical memory configured for this LPAR. |
SMT Threads | Number of SMT threads configured in the partition. The value
can be 1, 2, 4 or 8. Note: The maximum number of SMT threads per
processor is based on the Power® Architecture.
|
Shared Processor Mode | Indicates whether Shared Processor Mode is configured
for this partition. The possible values are:
|
Active Memory Sharing | Indicates whether Active Memory Sharing is Enabled or Disabled |
Active Memory Expansion | Indicates whether Active Memory Expansion is Enabled or Disabled |
Target Expanded Memory Size | Indicates the target expanded memory size in MB for the LPAR. The Target
Expanded Memory Size is the True Memory Size multiplied by the Target Memory Expansion Factor.
Note: This get displayed only when Active Memory
Expansion is enabled
|
Target Memory Expansion factor | Indicates the target memory expansion factor
configured for the LPAR. Note: This get displayed only when Active Memory Expansion
is enabled
|
System Resource Statistics
System Resource Statistics provides details about the system resource utilization from CPU/Memory Stand point. The following table shows various statistics related to system resource utilization
Item | Description |
---|---|
CPU Util | The Partition's processor utilization in the units of number
of physical processors. The percentage of utilization against the
Maximum Capacity is also reported. Note: If Active Memory Expansion is enabled,
the processor utilization due to memory compression / decompression
is also included
|
Virtual Memory Size | The Active Virtual Memory Size in MB. The percentage against the True Memory Size is also reported. |
True Memory In-Use | This is amount of the LPAR’s real physical (or logical) memory in MB. The percentage against the True Memory Size is also reported. |
Pinned Memory | This represents the pinned memory size in MB. The percentage against the True Memory Size is also reported. |
File Cache Size | This represents the non-computational file cache size in MB. The percentage against the True Memory Size is also reported. |
Available Memory | This represents the size of the memory available, in MB, for application execution. The percentage against the True Memory Size is also reported. |
Active Memory Expansion Statistics
Active Memory Expansion Statistics provides details about the Active Memory Expansion statistics. This section is only displayed if Active Memory Expansion has been enabled for the LPAR. The following table describes the various statistics that are reported
Item | Description |
---|---|
AME processor Usage | The processor utilization for Active Memory Expansion activity in units of physical processors. It indicates the amount of processing capacity used for memory compression activity. The percentage of utilization against the Maximum Capacity is also reported. |
Compressed Memory | The total amount of virtual memory that is compressed. This is measured in MB. The percentage against the Target Expanded Memory Size is also reported. |
Compression Ratio | This represents how well the data is compressed in memory. A higher compression ratio indicates that the data compresses to a smaller size. For example, if 4 KB of data can be compressed down to 1 KB, then the compression ratio is 4.0. |
Deficit Memory Size | The size of the expanded memory, in MB, deficit for the LPAR. This is only displayed if the LPAR has a memory deficit. The percentage against the Target Expanded Memory Size is also reported. |
Active Memory Expansion Modeled Statistics
Active Memory Expansion Modeled Statistics provides details about the modeled statistics for Active Memory Expansion. The following table provides the information about the modeled statistics.
Item | Description |
---|---|
Modeled Expanded Memory Size | It represents the size of expanded memory that is used to produce the modeled statistics. |
Average Compression Ratio | It represents the average compression ratio of the in-memory data of the workload. This compression ratio is used to produce the modeled statistics. |
Modeled Expansion Factor | It represents the modeled target memory expansion factor. |
Modeled True Memory Size | It represents the modeled true memory size (real physical or logical memory) |
Modeled Memory Gain | It represents the amount of memory the partition can gain by enabling Active Memory Expansion for the reported modeled expansion factor |
AME processor Usage Estimate | It represents an estimate of the processor
that would be used for Active
Memory Expansion activity for the specified configuration. It
estimates the amount of processing capacity that would be used for
memory compression activity. The processor usage is reported in units
of physical processors. The percentage of utilization against the
Maximum Capacity is also reported. Note: This is just an estimate
and should only be used as guidance; the actual usage can be higher
or lower depending on the workload.
|
Modeled Implementation | It represents the processor implementation for which modeling is done. This is available only if the –O proc option is used. |
Recommendation
Recommendation provides details about the Active Memory Expansion configuration that would provide optimal benefits to the current running workload.
amepat can be started using the System Management Interface Tool (SMIT) smit amepat fast path to run this command.
Flags
Item | Description |
---|---|
-a | Specifies to auto-tune the expanded memory size for Active Memory Expansion
Modeled Statistics. When this option is selected, the Modeled Expanded
Memory Size is estimated based on the current memory usage of the
workload (excludes the available memory size). Note: The -a and -t options
are mutually exclusive.
|
-c max_ame_cpuusage% | Specifies the maximum Active
Memory Expansion processor usage in terms of percentage to be
used for producing the Modeled statistics & recommendation. Note: The
default maximum used is 15%. The -C and -c option
cannot be specified together. The -c and -e options
are mutually exclusive.
|
-C max_ame_cpuusage | Specifies the maximum Active
Memory Expansion processor usage in terms of number of physical
processors to be used for producing the Modeled statistics and recommendation.
Note: The -C and -c option cannot be specified together.
The -C and -e option are mutually exclusive.
|
-e startexpfactor:stopexpfactor:incexpfactor | Specifies the range of expansion factors to
be reported in the Active
Memory Expansion Modeled Statistics section.
Note: The -e option cannot be combined with -C or -c options.
|
-m min_mem_gain | Specifies the Minimum Memory Gain. This value is specified in MB. This value is used in determining the various possible expansion factors reported in the Modeled Statistics and also influence the produced recommendations. |
-M | Does not break the 64 KB page into 4 KB chunks and compresses the entire 64 KB
page when the workloads are modeled. Note: The -M flag can be specified only in
POWER8® processor-based servers, or
later.
|
-n num_entries | Specifies the number of entries that need to
be displayed in the Modeled Statistics. Note: When -e with incexpfactor specified
then -n value is ignored.
|
-N | Disable Active Memory Expansion Modeling (Workload Planning Capability) |
-O proc=processor implementation | Specifies the processor implementation for which
modeling is done. You can specify the following processor versions:
Note: The -O option cannot be specified with the –R option.
|
-P recfile | Process the specified recording file and generate report. |
-R recfile | Record the active memory expansion data in
the specified recording file. The recorded data can be post processed
later using the -P option. Note: Only -N option can
be combined with -R.
|
-t tgt_expmem_size | Specifies the Modeled Target Expanded Memory
Size. This makes the tool to use the user specified size for modeling
instead of the calculated one. Note: The -t and -a options
are mutually exclusive.
|
-u minuncompressedpoolsize | Specifies the minimum uncompressed pool size in MB. This value over-rides the
tool calculated value for producing Modeled Statistics. Note: This flag can be used only when Active Memory Expansion is disabled.
|
-v | Enables Verbose Logging. When specified a verbose
log file is generated, named as amepat_yyyymmddhmm.log, where yyyymmddhmm represents
the time of invocation. Note: The verbose log also contains detailed
information on various samples collected and hence the file will be
larger than the output generated by the tool.
|
Duration | Duration represents the amount of total time
the tool need to monitor the system before generating any reports.
Note: When duration is specified interval/samples cannot be specified.
The interval & samples will be determined by the tool automatically.
The actual monitoring time can be higher than the duration specified
based on the memory usage and access patterns of the workload.
|
Interval <Samples> | Interval represents the amount of sampling time,
Samples represents the number of samples need to be collected. Note: When
interval, samples are specified, duration is calculated automatically
as (interval x Samples). The actual monitoring time can be higher
than the duration specified based on the memory usage and access patterns
of the workload.
|
- The default behavior of the amepat command on a modeling report would be as follows:
- When the amepat command is run on POWER7® or earlier processor implementations, the default modeled processor implementation is POWER7.
- When the amepat command is run on a processor implementation later than POWER7, the default modeled processor is the same as the processor implementation where it runs.
- When AME is enabled, the -O proc option can be used to model processors equal or newer than the processor implementation where the amepat command is running.
- The amepat command facilitates the user to provide minimum and/or maximum values for certain flags (like the -e flag) that helps alter the modeling behavior. The specified values are taken as suggested values by the amepat command. The amepat command overrides these values if they are not within the permissible ranges determined by the command during its course of execution.
Exit Status
Item | Description |
---|---|
0 | The command completed successfully. |
>0 | An error occurred. |
ATTENTION: RBAC users and Trusted AIX users:
This command can perform privileged operations. Only privileged users can run privileged operations.
Examples
- To display Active Memory Expansion Monitoring
only report, enter:
amepat
- To monitor the workload, for the duration of 16 minutes with 8
minute sampling interval and 2 samples, generate report for Workload
Planning, enter:
amepat 8 2
- To monitor the workload for a duration of 16 minutes and generate Active Memory Expansion
report for Workload Planning with modeled memory expansion factors
between 1.5 and 3 at 0.5 incremental factor, enter:
amepat –e 1.50:3.00:0.5 16
- To monitor the workload for a duration of 16 minutes and generate Active Memory Expansion
report for Workload Planning with capping the modeled AME processor
usage to 30%, enter:
amepat –c 30 16
- To monitor the workload for a duration of 16 minutes and generate Active Memory Expansion
report for Workload Planning with starting modeled memory gain of
1000 MB, enter:
amepat –m 1000 16
- To monitor the workload for a duration of 16 minutes and generate Active Memory Expansion
report for Workload Planning by modeling a minimum uncompressed pool
size 2000 MB, enter:
amepat –u 2000 16
- To use the recording mode of amepat to generate the recording file and generate reports
with various filters, enter:
Start Recording for a duration of 60 minutes.
amepat -R myrecord_amepat 60
Note: The recording mode will switch itself into background process.Generate Report for Workload Planning
amepat -P myrecord_amepat
Generate Report for Workload Planning with the modeled memory expansion factors ranging between 2 to 4 with 0.5 delta factor
amepat -e 2.0:4.0:0.5 -P myrecord_amepat
Generate Monitoring only report
amepat -N -P myrecord_amepat
- To disable Workload Planning Capability & monitor the system
for 30 minutes, enter:
amepat -N 30
- To monitor the workload for a duration of 60 minutes
and to model for Processor Implementation P8, enter the following
command:
amepat –O proc=P8 60