When troubleshooting memory issues it sometimes is necessary to change the Windows pagefile to something different that the default settings. In this case I would like the pagefile to have the same size as the amount of physical memory and be placed on another drive.
(Default Windows pagefile)
Add custom pagefile
To disable „Automatically manage paging file size for all drives“ WMI can be used with the Win32_ComputerSystem class. I use it with a WMI CmdLet and not a CIM CmdLet as the put-method does not work with a CIM CmdLet.
$PageFile = Get-WmiObject -Class Win32_ComputerSystem -EnableAllPrivileges
$PageFile.AutomaticManagedPagefile = $false
$PageFile.put() | Out-Null
When the automation is disabled then the pagefile can be configured. In this case I am setting Initial and Maximum size both to the amount of physical memory. It is recommend (1) that the max pagefile is set to the amount of physical memory plus 257 MB. All this can be done with CIM and WMI CmdLets. The memory size from Win32_PhysicalMemory is in Bytes where the properties to Win32_PageFileSetting are in MB and this is why I convert to MB in the script.
$PhysicalMemory = Get-CimInstance -ClassName Win32_PhysicalMemory
[int]$PageFileSize = 0
foreach ( $Device in $PhysicalMemory ) { $PageFileSize += $Device.Capacity/1MB }
$PageFileSize += 257
"Setting PageFile size to $PageFileSize MB..."
$PageFileSet = Get-WmiObject -Class Win32_PageFileSetting
#$PageFileSet | fl *
$PageFileSet.InitialSize = $PageFileSize
$PageFileSet.MaximumSize = $PageFileSize
$PageFileSet.Put() | Out-Null
(Windows pagefile custom configuration)
If the server is with NUMA configuration then Win32_PhysicalMemory will return an array of memory devices. This is why I traverse the output with foreach. In my case the computer is a virtual machine with eight vCores on eight vSockets and it looks like Windows Server (2016) split that in four vNUMA nodes as I get an array of four elements from Win32_PhysicalMemory. My workstation is the host and runs with one 12C/24T processor.
There must be enough free storage. If that is not available the Win32_PageFileSetting.Put() will fail with this not usefull message:
Exception calling "Put" with "0" argument(s): "Value out of range "
At line:12 char:1
+ $PageFileSet.Put() | Out-Null
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : DotNetMethodException
To activate the configuration the server needs a reboot.
(Windows pagefile custom configuration activated)
The custom pagefile is added in the right place. But the default pagefile still exist.
Remove default pagefile
The default pagefile is removed with the method Delete() to the specific selected default pagefile by a WQL statement.
$defaultPageFile = Get-WmiObject -Query "SELECT * FROM Win32_PageFileSetting WHERE Name = 'C:\\pagefile.sys'"
#$defaultPageFile | fl *
$defaultPageFile.Delete()
This takes effect with another reboot. This reboot also remove the file "pagefile.sys" from the root of the C-drive.
(Windows default pagefile deleted)
The methods to a WMI object like from Win32_PageFileSetting above does not show with Get-Member. But the documentation to the interface IWbemClassObject lists and describe the general methods to a WMI object.
Notes
(1) Microsoft: Overview of memory dump file options for Windows > Complete memory dump.
History
2025-06-01 : Custom pagefile and default pagefile are differelt.
2025-04-29 : 257 MB addition to pagefile size with reference to (1).
2025-02-24 : Post created
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