Writing CMTrace format Log files with Powershell

Anyone who has administered a little SCCM in their time, would be be familiar with the tool CMTrace or SMSTrace. CMTrace is a tool that comes with System Center Configuration Manager. It allows you to view the myriad of logs files that SCCM generates in a consistent and easy to read format. Being used to the log format that CMTrace generates, I thought it would be a great idea to use that format for logging Powershell script actions and errors.

I hunted around the web and found a few versions of a log function using CMTRace. The best implementation that I found was from Russ Slaten at the System Center Blog site. It works really well but I wanted to add some different functionality.

CMTrace.exe is part of the System Center 2012 R2 Configuration Manager Toolkit, which I believe anyone can download. If you have System Center Configuration Manager installed in your environment, you can also grab it from the \\”SiteServer”\Program Files\Microsoft Configuration Manager\tools\cmtrace.exe.

There are a few different use cases for when logging is handy: –

  • Running Powershell scripts as Scheduled Tasks.
  • Auditing automation centrally in a team environment.
  • The output of a log could be used as part of change management processes.
  • Debugging locally and remotely

I’ll start off by posting the script. Below I’ll go into some information that might help in using the script.

**NOTE: This has only been tested on Powershell v5.0. The information stream is a new feature of Powershell v5.0.**

Here is the script: –

I’ve included a help file inline to help with calling the function.

Where does the log file get created?

The function by default will log to $Env:temp\powershell-cmtrace.log. You can however pass a file location to the function if you would like to the log file in a different location.


What does the output look like on the host?

Here is an example.


Why does Error only log one line back to the host, where is all the ErrorRecord informaiton?

I wanted to write back to the host in a consistent fashion. The error record is still there I’m just not passing it back to the host. The full error record gets put in the log file and you can view that information by clicking on the Error entry and looking at the window down the bottom of CMTrace. Also, you can still access the error information in the host by using the $Error variable. If it were the last error you would access it by using the first index of the $Error variable. eg. $Error[0].


What does the output to the log file look like?

It looks like this. Notice the Error information is in the box down the bottom.


I don’t want to see the output on the host, I just want it to log in the CMTrace format.

There is a parameter switch called WriteBackToHost. By default it’s set to True, but if you don’t want to see the output then set this to false.

How do I call this function?

To call this function, either dot source it, run it from ISE and then call it, put it in your profile or pop it in a module and Bob is your uncle.

Gimme some examples of how to use the Write-CMTracelog function.

Here are some examples of how you would use this advanced function that are in the help section of the function.


The below example shows how to output a verbose message.

This example shows how to use the Preference variables with the Write-CMTracelog function. It should obey any preference variables that are set in the same scope from where the function has been called.

This example shows how to use the function with a terminating error by using the $Error variable in the message parameter.


Hope this function helps you out. Feel free to use and modify to suit your needs.



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