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Win32_PerfRawData_PerfOS_Memory class

The Win32_PerfRawData_PerfOS_Memory raw performance data class provides raw data from performance counters that monitor physical and virtual memory on the computer. Virtual memory consists of the space in physical memory and on disk. Many of the memory counters monitor paging, which is the movement of pages of code and data between a disk and physical memory. Excessive paging, a symptom of a memory shortage, can cause delays which interfere with all system processes.

This class represents the Memory object in System Monitor. The original data source is the PerfOS performance library. The corresponding formatted data class is Win32_PerfFormattedData_PerfOS_Memory. Data is dynamically provided for this class from the performance library object by the WmiPerfInst provider.

Windows Server 2003 and Windows XP:  WMI data for this class is supplied by the Performance Counter Provider.

The following syntax is simplified from MOF code and shows all inherited properties, including the Frequency and Timestamp properties required for class display in System Monitor. For more information about required property qualifiers, see Property Qualifiers for Performance Counter Classes. For more information about CounterType values, see WMI Performance Counter Types.

Syntax

class Win32_PerfRawData_PerfOS_Memory : Win32_PerfRawData
{
  uint64 AvailableBytes;
  uint64 AvailableKBytes;
  uint64 AvailableMBytes;
  uint64 CacheBytes;
  uint64 CacheBytesPeak;
  uint32 CacheFaultsPerSec;
  string Caption;
  uint64 CommitLimit;
  uint64 CommittedBytes;
  uint32 DemandZeroFaultsPerSec;
  string Description;
  uint32 FreeSystemPageTableEntries;
  uint64 Frequency_Object;
  uint64 Frequency_PerfTime;
  uint64 Frequency_Sys100NS;
  string Name;
  uint32 PageFaultsPerSec;
  uint32 PageReadsPerSec;
  uint32 PagesInputPerSec;
  uint32 PagesOutputPerSec;
  uint32 PagesPerSec;
  uint32 PageWritesPerSec;
  uint32 PercentCommittedBytesInUse;
  uint32 PercentCommittedBytesInUse_Base;
  uint32 PoolNonpagedAllocs;
  uint64 PoolNonpagedBytes;
  uint32 PoolPagedAllocs;
  uint64 PoolPagedBytes;
  uint64 PoolPagedResidentBytes;
  uint64 SystemCacheResidentBytes;
  uint64 SystemCodeResidentBytes;
  uint64 SystemCodeTotalBytes;
  uint64 SystemDriverResidentBytes;
  uint64 SystemDriverTotalBytes;
  uint64 Timestamp_Object;
  uint64 Timestamp_PerfTime;
  uint64 Timestamp_Sys100NS;
  uint32 TransitionFaultsPerSec;
  uint32 WriteCopiesPerSec;
};

Members

The Win32_PerfRawData_PerfOS_Memory class has these types of members:

Properties

The Win32_PerfRawData_PerfOS_Memory class has these properties.

AvailableBytes
Data type: uint64
Access type: Read-only
Qualifiers: DisplayName ("Available Bytes") , CounterType (65792) , DefaultScale (6) , PerfDetail (300)

Amount of physical memory in bytes available to processes running on the computer. This value is calculated by summing space on the Zeroed, Free, and Standby memory lists. Free memory is ready for use; Zeroed memory is pages of memory filled with zeros to prevent later processes from seeing data used by a previous process. Standby memory is memory removed from a process's working set (its physical memory) on route to disk, but is still available to be recalled. This property displays the last observed value only; it is not an average.

For more information about using uint64 values in scripts, see Scripting in WMI.

AvailableKBytes
Data type: uint64
Access type: Read-only
Qualifiers: DisplayName ("Available KBytes") , CounterType (65792) , DefaultScale (0) , PerfDetail (300)

Amount of physical memory available to processes running on the computer, in kilobytes. It is calculated by summing space on the Zeroed, Free, and Standby memory lists. Free memory is ready for use; Zeroed memory contains memory pages filled with zeros to prevent later processes from seeing data used by a previous Process. Standby memory is memory removed from a process' working set (its physical memory) on route to disk, but is still available to be recalled. This property displays the last observed value only; it is not an average.

For more information about using uint64 values in scripts, see Scripting in WMI.

AvailableMBytes
Data type: uint64
Access type: Read-only
Qualifiers: DisplayName ("Available MBytes") , CounterType (65792) , DefaultScale (0) , PerfDetail (300)

Amount of physical memory available to processes running on the computer, in megabytes. It is calculated by summing space on the Zeroed, Free, and Standby memory lists. Free memory is ready for use; Zeroed memory contains memory pages filled with zeros to prevent later processes from seeing data used by a previous process. Standby memory is memory removed from a process' working set (its physical memory) on route to disk, but is still available to be recalled. This property displays the last observed value only; it is not an average.

For more information about using uint64 values in scripts, see Scripting in WMI.

CacheBytes
Data type: uint64
Access type: Read-only
Qualifiers: DisplayName ("Cache Bytes") , CounterType (65792) , DefaultScale (-5) , PerfDetail (200)

Number of bytes currently being used by the file system cache. The file system cache is an area of physical memory that stores recently used pages of data for applications. The operating system continually adjusts the size of the cache, making it as large as it can while still preserving the minimum required number of available bytes for processes. This property displays the last observed value only; it is not an average.

For more information about using uint64 values in scripts, see Scripting in WMI.

CacheBytesPeak
Data type: uint64
Access type: Read-only
Qualifiers: DisplayName ("Cache Bytes Peak") , CounterType (65792) , DefaultScale (-5) , PerfDetail (200)

Maximum number of CacheBytes after the system was last restarted. This value might be larger than the current size of the cache. CacheBytes is the sum of the System Cache Resident Bytes, System Driver Resident Bytes, System Code Resident Bytes, and Pool Paged Resident Bytes counters. This property displays the last observed value only; it is not an average.

For more information about using uint64 values in scripts, see Scripting in WMI.

CacheFaultsPerSec
Data type: uint32
Access type: Read-only
Qualifiers: DisplayName (" ") , CounterType (65536) , DefaultScale (0) , PerfDetail (100)

Number of faults which occur when a page sought in the file system cache is not found there and must be retrieved from elsewhere in memory (soft fault) or from disk (hard fault). The file system cache is an area of physical memory that stores recently used pages of data for applications. Cache activity is a reliable indicator of most application I/O operations. This property counts the number of faults without regard for the number of pages faulted in each operation.

Caption
Data type: string
Access type: Read-only

Short textual description for the statistic or metric. This property is inherited from CIM_StatisticalInformation.

CommitLimit
Data type: uint64
Access type: Read-only
Qualifiers: DisplayName ("Commit Limit") , CounterType (65792) , DefaultScale (-6) , PerfDetail (400)

Amount of virtual memory, in bytes, that can be committed without having to extend the paging file(s). (Committed memory is physical memory for which space has been reserved on the disk paging files. Each logical disk drive has one paging file.) If the paging file(s) are be expanded, the CommitLimit value increases accordingly. This property displays the last observed value only; it is not an average.

For more information about using uint64 values in scripts, see Scripting in WMI.

CommittedBytes
Data type: uint64
Access type: Read-only
Qualifiers: DisplayName ("Committed Bytes") , CounterType (65792) , DefaultScale (-6) , PerfDetail (300)

Amount of committed virtual memory, in bytes. Committed memory is physical memory for which space has been reserved on the disk paging file in case it must be written back to disk. This property displays the last observed value only; it is not an average.

For more information about using uint64 values in scripts, see Scripting in WMI.

DemandZeroFaultsPerSec
Data type: uint32
Access type: Read-only
Qualifiers: DisplayName ("Demand Zero Faults/sec") , CounterType (272696320) , DefaultScale (-1) , PerfDetail (400)

Number of page faults that require a zeroed page to satisfy the fault. Zeroed pages, pages emptied of previously stored data and filled with zeros, are an operating system security feature. They prevent processes from seeing data stored by earlier processes that used the memory space. The operating system maintains a list of zeroed pages to accelerate this process. This property counts numbers of faults, without regard to the numbers of pages retrieved to satisfy the fault. This property displays the difference between the values observed in the last two samples, divided by the duration of the sample interval.

Description
Data type: string
Access type: Read-only

Textual description of the statistic or metric. This property is inherited from CIM_StatisticalInformation.

FreeSystemPageTableEntries
Data type: uint32
Access type: Read-only
Qualifiers: DisplayName ("Free System Page Table Entries") , CounterType (65536) , DefaultScale (-2) , PerfDetail (400)

Number of page table entries not being used by the system. This property displays the last observed value only; it is not an average.

Frequency_Object
Data type: uint64
Access type: Read-only

Frequency, in ticks per second, of Timestamp_Object. This property is defined by the provider. This property is inherited from Win32_Perf.

For more information about using uint64 values in scripts, see Scripting in WMI.

Frequency_PerfTime
Data type: uint64
Access type: Read-only

Frequency, in ticks per second, of Timestamp_Perftime. A value could be obtained by calling the Windows function QueryPerformanceCounter. This property is inherited from Win32_Perf.

For more information about using uint64 values in scripts, see Scripting in WMI.

Frequency_Sys100NS
Data type: uint64
Access type: Read-only

Frequency, in ticks per second, of Timestamp_Sys100NS (10000000). This property is inherited from Win32_Perf.

For more information about using uint64 values in scripts, see Scripting in WMI.

Name
Data type: string
Access type: Read-only
Qualifiers: Key, MaxLen (256)

Label by which the statistic or metric is known. When sub-classed, the property can be overridden to be a key property. This property is inherited from CIM_StatisticalInformation.

PageFaultsPerSec
Data type: uint32
Access type: Read-only
Qualifiers: DisplayName ("Page Faults/sec") , CounterType (272696320) , DefaultScale (-1) , PerfDetail (100)

Overall rate at which faulted pages are handled by the processor. A page fault occurs when a process requires code or data that is not in its working set (its space in physical memory). This property includes both hard faults (those that require disk access) and soft faults (where the faulted page is found elsewhere in physical memory.) Most processors can handle large numbers of soft faults without consequence. However, hard faults can cause significant delays. This property displays the difference between the values observed in the last two samples, divided by the duration of the sample interval.

PageReadsPerSec
Data type: uint32
Access type: Read-only
Qualifiers: DisplayName ("Page Reads/sec") , CounterType (272696320) , DefaultScale (0) , PerfDetail (300)

Number of times the disk was read to resolve hard page faults. (Hard page faults occur when a process requires code or data that is not in its working set or elsewhere in physical memory, and must be retrieved from disk.) This property was designed as a primary indicator of the kinds of faults that cause system-wide delays. It includes read operations to satisfy faults in the file system cache (usually requested by applications) and in non-cached mapped memory files. This property counts the number of read operations, without regard to the number of pages retrieved by each operation. This property displays the difference between the values observed in the last two samples, divided by the duration of the sample interval.

PagesInputPerSec
Data type: uint32
Access type: Read-only
Qualifiers: DisplayName ("Pages Input/sec") , CounterType (272696320) , DefaultScale (0) , PerfDetail (100)

Number of pages read from disk to resolve hard page faults. (Hard page faults occur when a process requires code or data that is not in its working set or elsewhere in physical memory, and must be retrieved from disk.) This property was designed as a primary indicator of the kinds of faults that cause system-wide delays. It includes pages retrieved to satisfy faults in the file system cache (usually requested by applications) and in non-cached mapped memory files. This property counts the numbers of pages, and can be compared to other counts of pages, such as the PageFaultsPerSec property in Win32_PerfFormattedData_PerfOS_Memory, without conversion. This property displays the difference between the values observed in the last two samples, divided by the duration of the sample interval.

PagesOutputPerSec
Data type: uint32
Access type: Read-only
Qualifiers: DisplayName ("Pages Output/sec") , CounterType (272696320) , DefaultScale (0) , PerfDetail (200)

Number of pages written to disk to free up space in physical memory. Pages are written back to disk only if they are changed in physical memory, so they are likely to hold data, not code. A high rate of pages output might indicate a memory shortage. The operating system writes more pages back to disk to free up space when physical memory is in short supply. This property counts numbers of pages, and can be compared to other counts of pages, without conversion. This property displays the difference between the values observed in the last two samples, divided by the duration of the sample interval.

PagesPerSec
Data type: uint32
Access type: Read-only
Qualifiers: DisplayName ("Pages/sec") , PerfDefault, CounterType (272696320) , DefaultScale (0) , PerfDetail (100)

Number of pages read from or written to the disk to resolve hard page faults. (Hard page faults occur when a process requires code or data that is not in its working set or elsewhere in physical memory, and must be retrieved from disk.) This property was designed as a primary indicator of the kinds of faults that cause system-wide delays. It is the sum of the PagesInputPerSec and PagesOutputPerSec properties in the Win32_PerfFormattedData_PerfOS_Memory class. It is counted in numbers of pages, so it can be compared to other counts of pages, such as the PageFaultsPerSec property in Win32_PerfFormattedData_PerfOS_Memory, without conversion. It includes pages retrieved to satisfy faults in the file system cache (usually requested by applications) non-cached mapped memory files. This property displays the difference between the values observed in the last two samples, divided by the duration of the sample interval.

PageWritesPerSec
Data type: uint32
Access type: Read-only
Qualifiers: DisplayName ("Page Writes/sec") , CounterType (272696320) , DefaultScale (0) , PerfDetail (300)

Number of times pages were written to disk to free up space in physical memory. Pages are written to disk only if they are changed while in physical memory, so they are likely to hold data, not code. This property counts write operations, without regard to the number of pages written in each operation. This property displays the difference between the values observed in the last two samples, divided by the duration of the sample interval.

PercentCommittedBytesInUse
Data type: uint32
Access type: Read-only
Qualifiers: DisplayName ("% Committed Bytes In Use") , CounterType (537003008) , DefaultScale (0) , PerfDetail (300)

Ratio of Memory: Committed Bytes to Memory: Commit Limit. (Committed memory is physical memory in use for which space has been reserved in the paging file should it must be written to disk. The commit limit is determined by the size of the paging file. If the paging file is enlarged, the commit limit increases, and the ratio is reduced.) This property displays the current percentage value only; it is not an average.

PercentCommittedBytesInUse_Base
Data type: uint32
Access type: Read-only
Qualifiers: DisplayName (" ") , CounterType (1073939459) , DefaultScale (0) , PerfDetail (300)

Base value for PercentCommittedBytesInUse.

PoolNonpagedAllocs
Data type: uint32
Access type: Read-only
Qualifiers: DisplayName ("Pool Nonpaged Allocs") , CounterType (65536) , DefaultScale (-2) , PerfDetail (400)

Number of calls to allocate space in the non-paged pool, regardless of the amount of space allocated in each call. The non-paged pool is an area of system memory area for objects that cannot be written to disk, and must remain in physical memory as long as they are allocated. This property displays the last observed value only; it is not an average.

PoolNonpagedBytes
Data type: uint64
Access type: Read-only
Qualifiers: DisplayName ("Pool Nonpaged Bytes") , CounterType (65792) , DefaultScale (-5) , PerfDetail (200)

Number of bytes in the non-paged pool, an area of system memory (physical memory used by the operating system) for objects that cannot be written to disk, but must remain in physical memory as long as they are allocated. Memory: Pool Nonpaged Bytes is calculated differently than Process: Pool Nonpaged Bytes, so it might not equal Process: Pool Nonpaged Bytes: _Total. This property displays the last observed value only; it is not an average.

For more information about using uint64 values in scripts, see Scripting in WMI.

PoolPagedAllocs
Data type: uint32
Access type: Read-only
Qualifiers: DisplayName ("Pool Paged Allocs") , CounterType (65536) , DefaultScale (-2) , PerfDetail (1200)

Number of calls to allocate space in the paged pool, regardless of the amount of space allocated in each call. The paged pool is an area of system memory (physical memory used by the operating system) for objects that can be written to disk when they are not being used. This property displays the last observed value only; it is not an average.

PoolPagedBytes
Data type: uint64
Access type: Read-only
Qualifiers: DisplayName ("Pool Paged Bytes") , CounterType (65792) , DefaultScale (-5) , PerfDetail (200)

Number of bytes in the paged pool, an area of system memory (physical memory used by the operating system) for objects that can be written to disk when they are not being used. The PoolPagedBytes property in the Win32_PerfFormattedData_PerfOS_Memory class is calculated differently than the PoolPagedBytes property in Win32_PerfFormattedData_PerfProc_Process, so it might not equal the total of PoolPagedBytes for all instances of Win32_PerfFormattedData_PerfProc_Process. This property displays the last observed value only; it is not an average.

For more information about using uint64 values in scripts, see Scripting in WMI.

PoolPagedResidentBytes
Data type: uint64
Access type: Read-only
Qualifiers: DisplayName ("Pool Paged Resident Bytes") , CounterType (65792) , DefaultScale (-5) , PerfDetail (200)

Current size of paged pool in bytes. The paged pool is an area of system memory (physical memory used by the operating system) for objects that can be written to disk when they are not being used. Space used by the paged and nonpaged pools are taken from physical memory, so a pool that is too large denies memory space to processes. This property displays the last observed value only; it is not an average.

For more information about using uint64 values in scripts, see Scripting in WMI.

SystemCacheResidentBytes
Data type: uint64
Access type: Read-only
Qualifiers: DisplayName ("System Cache Resident Bytes") , CounterType (65792) , DefaultScale (-5) , PerfDetail (200)

Number of bytes of pageable operating system code in the file system cache. This value is a component of Memory: System Code Resident Bytes which represents all pageable operating system code that is currently in physical memory. This property displays the last observed value only; it is not an average.

For more information about using uint64 values in scripts, see Scripting in WMI.

SystemCodeResidentBytes
Data type: uint64
Access type: Read-only
Qualifiers: DisplayName ("System Code Resident Bytes") , CounterType (65792) , DefaultScale (-5) , PerfDetail (200)

Number of bytes of operating system code currently in physical memory that can be written to disk when not in use. This value is a component of System Code Total Bytes, which also includes operating system code on disk. System Code Resident Bytes (and System Code Total Bytes) does not include code that must remain in physical memory and cannot be written to disk. This property displays the last observed value only; it is not an average.

For more information about using uint64 values in scripts, see Scripting in WMI.

SystemCodeTotalBytes
Data type: uint64
Access type: Read-only
Qualifiers: DisplayName ("System Code Total Bytes") , CounterType (65792) , DefaultScale (-5) , PerfDetail (200)

Number of bytes of pageable operating system code currently in virtual memory. It is a measure of the amount of physical memory being used by the operating system that can be written to disk when not in use. This value is calculated by summing the bytes in Ntoskrnl.exe, Hal.dll, the boot drivers, and file systems loaded by Ntldr/osloader. This property does not include code that must remain in physical memory and cannot be written to disk. This property displays the last observed value only; it is not an average.

For more information about using uint64 values in scripts, see Scripting in WMI.

SystemDriverResidentBytes
Data type: uint64
Access type: Read-only
Qualifiers: DisplayName ("System Driver Resident Bytes") , CounterType (65792) , DefaultScale (-5) , PerfDetail (200)

Number of bytes of pageable physical memory being used by device drivers. It is the working set (physical memory area) of the drivers. This value is a component of Memory: System Driver Total Bytes, which also includes driver memory that has been written to disk. Neither System Driver Resident Bytes nor System Driver Total Bytes includes memory that cannot be written to disk.

For more information about using uint64 values in scripts, see Scripting in WMI.

SystemDriverTotalBytes
Data type: uint64
Access type: Read-only
Qualifiers: DisplayName ("System Driver Total Bytes") , CounterType (65792) , DefaultScale (-5) , PerfDetail (200)

Number of bytes of pageable virtual memory currently being used by device drivers. (Pageable memory can be written to disk when it is not being used.) It includes physical memory (Memory: System Driver Resident Bytes) and code and data paged to disk. It is a component of Memory: System Code Total Bytes. This property displays the last observed value only; it is not an average.

For more information about using uint64 values in scripts, see Scripting in WMI.

Timestamp_Object
Data type: uint64
Access type: Read-only

Object-defined timestamp, defined by the provider. This property is inherited from Win32_Perf.

For more information about using uint64 values in scripts, see Scripting in WMI.

Timestamp_PerfTime
Data type: uint64
Access type: Read-only

High Performance counter timestamp. A value could be obtained by calling the Windows function QueryPerformanceCounter. This property is inherited from Win32_Perf.

For more information about using uint64 values in scripts, see Scripting in WMI.

Timestamp_Sys100NS
Data type: uint64
Access type: Read-only

Timestamp value in 100 nanosecond units. This property is inherited from Win32_Perf.

For more information about using uint64 values in scripts, see Scripting in WMI.

TransitionFaultsPerSec
Data type: uint32
Access type: Read-only
Qualifiers: DisplayName ("Transition Faults/sec") , CounterType (272696320) , DefaultScale (-1) , PerfDetail (400)

Number of page faults resolved by recovering pages that were on the modified page list, on the standby list, or being written to disk at the time of the page fault. The pages were recovered without additional disk activity. Transition faults are counted in the numbers of faults, without regard for the number of pages faulted in each operation. This property displays the difference between the values observed in the last two samples, divided by the duration of the sample interval.

WriteCopiesPerSec
Data type: uint32
Access type: Read-only
Qualifiers: DisplayName ("Write Copies/sec") , CounterType (272696320) , DefaultScale (0) , PerfDetail (400)

Number of page faults caused by attempts to write that have been satisfied by copying the page from elsewhere in physical memory. This is an economical way of sharing data because pages are only copied when they are written to; otherwise, the page is shared. This property counts the number of copies, without regard for the number of pages copied in each operation. This property displays the difference between the values observed in the last two samples, divided by the duration of the sample interval.

Remarks

All classes derived from Win32_Perf are designed to be used with a refresher object. For more information about how to create and use a refresher object in C++, see Accessing Performance Data in C++. For more information about how to create and use a refresher object using scripts, see Refreshing WMI Data in Scripts.

The performance class and property qualifiers determine how to interpret the class data. For more information, see Class Qualifiers for Performance Counter Classes and Property Qualifiers for Performance Counter Classes.

Examples

For script code examples, see WMI Tasks for Scripts and Applications and the TechNet ScriptCenter Script Repository.

For C++ code examples, see WMI C++ Application Examples.

Requirements

Minimum supported client

Windows XP

Minimum supported server

Windows Server 2003

Namespace

\root\CIMV2

DLL

WmiPerfInst.dll;
WbemPerf.dll on Windows Server 2003 and Windows XP

See also

Performance Counter Classes
Accessing WMI Preinstalled Performance Classes
WMI Tasks: Performance Monitoring
Accessing Performance Data in Script

 

 

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