Active Memory™ Expansion Planning and Advisory Tool amepat reports Active Memory Expansion information and statistics as well as provides advisory report that assists in planning the use of Active Memory Expansion for an existing workload.
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 ] [ -N ] [-O proc=<processor implementation> ][{ [ -P recfile ] | [ Duration ] | [ Interval <Samples> ]}]
amepat [ -N ] [ -R recfile ] {[ Duration] | [ Interval <Samples>]}
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.
amepat can be run on all versions of IBM® Power Systems™ supported by AIX 6.1. It includes systems using POWER4, POWER5, POWER6®, or POWER7® family processors.
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 or 4. |
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 Diabled |
Active Memory Expansion | Indicates whether Active Memory Expansion is Enabled or Diabled |
Target Expanded Memory Size | Indicates the target expanded memory size in
MegaBytes 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 MegaBytes. 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 MegaBytes. The percentage against the True Memory Size is also reported. |
Pinned Memory | This represents the pinned memory size in MegaBytes. The percentage against the True Memory Size is also reported. |
File Cache Size | This represents the non-computational file cache size in MegaBytes. The percentage against the True Memory Size is also reported. |
Available Memory | This represents the size of the memory available, in MegaBytes, 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 MegaBytes. 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 Kilobyte of data can be compressed down to 1 Kilobyte, then the compression ratio is 4.0. |
Deficit Memory Size | The size of the expanded memory, in MegaBytes, 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.
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 Megabytes. This value is used in determining the various possible expansion factors reported in the Modeled Statistics & also influence the produced recommendations. |
-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 Megabytes. 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.
|
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.
amepat
amepat 8 2
amepat –e 1.50:3.00:0.5 16
amepat –c 30 16
amepat –m 1000 16
amepat –u 2000 16
Start Recording for a duration of 60 minutes.
amepat –R myrecord_amepat 60
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
amepat -N 30