So this is how you do it:

Go to the “Authoring” space of OpsMgr 2007 Operations Console.Select the “Management Pack objects”, then “Monitors” node. Right click and choose “Create a monitor” -> “Unit Monitor”.
You get the “Create a monitor” wizard open:

Choose to create a two-states unit monitor based on a script. Creating a three- state monitor would be pretty similar, but I’ll show you the most simple one.Also, choose a Management pack that will contain your script and unit monitor, or create a new management pack.

Choose a “monitor target” (object classes or instances – see this webcast about targeting rules and monitors: www.microsoft.com/winme/0703/28666/Target_Monitoring_Edit… ) and the aggregate rollup monitor you want to roll the state up to.

Choose a name for your script, complete with a .VBS extension, and write the code of the script in the rich text box:

As the sample code and comments suggest, you should use a script that checks for the stuff you want it to check, and returns a “Property Bag” that can be later interpreted by OpsMgr workflow to change the monitor’s state.This is substantially different than scripting in MOM 2005, where you could only launch scripts as responses, loosing all control over their execution.

For demonstration purpose, use the following script code:

On Error Resume Next
Dim oAPI, oBag
Set oAPI = CreateObject(“MOM.ScriptAPI”)
Set oBag = oAPI.CreateTypedPropertyBag(StateDataType)
Const FOR_APPENDING = 8
strFileName = “c:\testfolder\testfile.txt”
strContent = “test “
Set objFS = CreateObject(“Scripting.FileSystemObject”)
Set objTS = objFS.OpenTextFile(strFileName,FOR_APPENDING)
If Err.Number <> 0 Then
Call oBag.AddValue(“State”,”BAD”)Else
Call oBag.AddValue(“State”,”GOOD”)
objTS.Write strContent
End If
Call oAPI.Return(oBag)

The script will try to write into the file c:\testfolder\testfile.txt.If it finds the file and manages to write (append text) to it, it will return the property “State” with a value of “GOOD”.If it fails (for example if the file does not exist), it will return the property “State” with a value of “BAD”.

In MOM 2005 you could only let script generate Events or Alerts directly as a mean to communicate their results back to the monitoring engine. In OpsMgr 2007 you can let your script spit out a property bag and then continue the monitoring workflow and decide what to do depending on the script’s result.

So the next step is to go and check for the value of the property we return in the property bag, to determine which status the monitor will have to assume.

We use the syntax Property[@Name='State'] in the parameter field, and we search for a content that means an unhealthy condition:

Or for the healty one:

Then we decide which status will the monitor have to assume in the healty and unhealty conditions (Green/Yellow or Green/Red usually)

Optionally, we can decide to raise an Alert when the status changes to unhealthy, and close it again when it goes back to healty.

Now our unit monitor is done.All we have to do is waiting it gets pushed down to the agent(s) that should execute it, and wait for its status to change.In fact it should go to the unhealthy state first.To test that it works, just create the text file it will be searching for, and wait for it to run again, and the state should be reset to Healthy.

This post was orginally posted at http://www.muscetta.com/2007/05/10/create-a-script-based-unit-monitor-in-opsmgr2007-via-the-gui/ I had been looking for a good SCOM vb script article for a long time. I figured I would re-post it here becuase his was so difficult to find. I give Daniele Muscetta full credit for this.