Monday, March 22, 2010

AEM: how to remove it?

Sometime ago I had a customer who had AEM in place but didn’t want it anymore. So how to remove AEM? I mean, disabling it isn’t difficult at all. But how to get rid of the many computers with an Unknown Status which got there because they were AEM ‘clients’? It took me a while to crack it. Had some help from Kevin Holman but even that didn’t help. And then some months later, by accident, I bumped into the solution. So this posting will be about how to remove all the computers with Unknown Status in SCOM which got there because of AEM.

First, how to disable AEM? Actually, it is this blog posting in reverse. So:

  1. Remove the GPO containing the AEM settings
    Wait some days for this change to take effect since not all client systems will be running on the day you change the GPO. So patience is needed here. For this customer I waited a week before continuing with the next steps. 

  2. Disable Client Monitoring on the SCOM Management Server
    Go to the Administration pane > Administration > Device Management > Management Servers. Select the MS handles AEM and right click it > select Disable Client Monitoring
    > Click Yes. It takes some time in order to complete. No message will be shown.

  3. Remove the share
    Now the share from the folder containing the ErrorData can be removed. Per OS this is done in a different kind of way.

  4. Permissions
    Adjust the permissions on the folder containing the ErrorData so the two Global Groups created by AEM (AEMAgent & AEMUsers) can be deleted from AD and the Domain Admins do have full permissions on that folder and its contents.
  5. Removal
    This last step is permanent. So think about it before proceeding. Remove the folder containing the ErrorData.

So AEM is disabled now. However, the amount of computers with an Unknown Status remains the same. So how to get this number down? As already stated, by accident I found the solution when configuring the Exchange 2007 MP.

In a nutshell this is what happened.

As you know the Exchange 2007 MP is disabled by default when imported. It only runs a Discovery process known as the ‘Discovery Helper’. With this process one can see whether the correct Exchange 2007 servers are discovered and correct it when needed.

At the customers site where AEM was removed, this MP ran the Discovery Helper process and some non-Exchange 2007 servers were discovered. So I created an override, disabling the Discovery Helper process.

Then I had to empty the group which became populated based on that discovery. For that a PS one-liner is needed: Remove-DisabledMonitoringObject.

I had run this PS cmdlet sometimes before and it always ran fast. But now it took some time to run and the RMS took a big hit. The cmdlet was finished after 15+ minutes but then I had a nice surprise: the amount of computers with the Unknown Status was reduced from a couple of thousand to less then 20! All the computers that were previously AEM Clients got groomed out!

I must add that I have experienced this only once (Until now I have removed AEM only one time) AND that there were some months of time between the date I removed/disabled AEM and imported the Exchange 2007 MP. So I do not know whether this PS cmdlet will help right after having removed/disabled AEM but is still worth sharing.

Let me know about your experiences so I can update this posting accordingly.


kgmqt said...

Everything appeared to have worked fine, but I am getting a few of these occationally:

Health Service Modules event ID 10925

CrashListenerPA module finds fileShare is not reachable/accessible or validation failed.

Marnix Wolf said...

Hi Kgmgt

Looks like an issue with the share. Is the server hosting the share too busy, are there any network issues like congestions?