WMI tests are based on based on Windows Management Instrumentation. The WMI technology allows network monitoring tools to manage and control various resources in the network. WMI test can help in managing running processes, registry settings, operating system settings, running services, hard drives, network components and many more system parameters.

WMI Test Properties

"Basic" WMI test properties can be set in the "Test Properties" dialog.

Specific WMI test properties include:

"Host" - monitored host name or IP address.
"Namespace" - the default WMI test namespace is "root\cimv2".
"WQL query" - the query in Windows Management Instrumentation Query Language that will be performed by the WMI test.
"Test pass condition" - set the condition of WMI test passing, by editing the [Select field], [Select condition] and [Enter value] values.
"When instance unavailable" - in case if the WMI test can not be performed due to unavailable instance, the test can be considered as passed, failed, or return previous test results.

Useful WMI Query Examples

WMI queries can be used for monitoring various system parameters on remote hosts. Here system administrators can find examples of useful WMI queries:

WMI Query for checking amount of free physical memory (Kb)

Use this WMI query for performing monitoring of free physical memory on remote hosts:
Select FreePhysicalMemory from Win32_OperatingSystem

WMI Query for managing system paging

Number, in kilobytes, that can be mapped into the operating system paging files without causing any other pages to be swapped out.
Select FreeSpaceInPagingFiles from Win32_OperatingSystem

WMI Query for checking available virtual memory on remote hosts

Number, in kilobytes, of virtual memory currently unused and available:
Select FreeVirtualMemory from Win32_OperatingSystem

WMI Query for tracking system memory necessary for process to function efficiently

Amount of memory in bytes that a process needs to execute efficiently:
Select WorkingSetSize from Win32_Process where Name = 'ProcessName'

WMI Query for monitoring page file space used by processes

Whith the help of this query you can perform monitoring of amount of page file space that a process is using currently. This value is consistent with the VMSize value in TaskMgr.exe
Select PageFileUsage from Win32_Process where Name = 'ProcessName'

WMI Query for monitoring idle CPU percentage

This request returns the idle percentage of the CPU:
Select PercentProcessorTime from Win32_PerfFormattedData_PerfProc_Process where name='idle'

WMI System requirements

The following versions of Windows do have the WMI pre-installed:
Windows 7
Windows Vista
Windows Server 2008
Windows Server 2003
Windows 2000
Windows XP
Windows ME