Old Exchange 2010 RTM MP causes config churn

****  4/7/2011  There is a new version of the Exchange 2010 MP for SP1 out now.  This new updated version does not have the config churn issues.



I wrote about config churn and the impact it can have on a management group here:  http://blogs.technet.com/b/kevinholman/archive/2009/10/05/what-is-config-churn.aspx


There are two discoveries in the Exchange 2010 RTM MP version 14.0.650.8 that cause some significant config churn.  This is being addressed and resolved in a future MP which should be shipping fairly soon, which will support Exchange 2010 SP1.  However, in the meantime you might want to take action, especially if your Exchange 2010 environment is growing.  I have some customers where this is really starting to cause an impact. 

The two discoveries target the “Mailbox” class – and are:

  • Microsoft.Exchange.2010.Mailbox.MdbOwningServerLocalEntityDiscoveryRule
  • Microsoft.Exchange.2010.Mailbox.MdbOwningServerRemoteEntityDiscoveryRule

These run ever 14400 seconds by default (4 hours).  The problem is they collect some properties that change with every run of the discovery.  The commonly churning properties are:

  • DatabaseSize
  • DbFreeSpace
  • LogDriveFreeSpace



You might consider overriding these to run once per day (that is the maximum supported for this particular discovery) until this condition is resolved with an updated MP.  This will not solve the config churn, it will simply reduce the amount caused by this specific workflow.

Once per day is 86400 seconds.  If you try to set it for more than 86400, you will get an error from the Scheduler Data Source Module about the synch time error.  Thanks to Marnix Wolf for passing along this info about the 86400 seconds being the maximum.


FYI – I wrote about the new Exchange 2010 MP for SP1 here:  http://blogs.technet.com/b/kevinholman/archive/2011/04/07/exchange-2010-sp1-management-pack-ships-version-14-02-0071-0.aspx

This new version indeed does solve the config churn issue – as you can see in the screenshot below – new entities for the mailboxes are discovered – with NULL values for the old items that would change frequently, DB size, Free space, Log size, and AD Site:



Comments (13)

  1. Kevin Holman says:

    @Ramesh –

    This is a known issue with this MP – this MP has some unique properties in it that cause MPviewer some trouble when exporting to Excel.  MPViewer is essentially a reskit tool and does not have direct support, therefore is not always updated for every scenario.

    The workaround is to export this MP into HTML, and then you can port it into Excel if needed.

  2. Kevin Holman says:

    @Michael –

    I do not believe these are used – because in the upcoming version of this MP to support Exchange 2010 SP1, these values are no longer collected.  There is no easy way to "turn off" only these properties in our discovery – because the MP is sealed and these properties cannot be modified via overrides.  The only simple solution is to disable the discovery, and then recreate it in your own MP with these property collections set to NULL or Zero.  That said – with a new MP coming soon, I'd probably just override the frequency for now.

  3. Kevin Holman says:

    @Santosh – if you will see – I have updated the article – initially I made a mistake in recommending one week for frequency – since this discovery has a synch time set the meaximum frequency is 86400.

  4. Kevin Holman says:

    @Rajiv –

    I dont have any insight into the date of release, unfortunately.

  5. Kevin Holman says:

    Uri – the DB size is now hard coded to "zero" to stop the config churn.  By design.

  6. Michael Christiansen says:

    Hi Kevin, great blog,

    Are these values used by the monitors of the managementpack for alerting on low space?

    Im thinking of a way to completly disabling the collection of these properties.

    Kind regards,


  7. santosh says:

    Hi Kevin,

    I setup the override as mentioned by Kevin and You but getting recurring interval can not be greater than the full re-sync interval for the schedule error. I changed it back to 86400. Do I have to make the change on sync time as well. It is set to default 00:00. Thank you very much.

    The Microsoft Operations Manager Scheduler Data Source Module failed to initialize because the recurring interval can not be greater than the full re-sync interval for the schedule.

    Recurring Interval Length (seconds): 604800

    Full Re-Sync Interval Length (seconds): 86400

    One or more workflows were affected by this.

    Workflow name: Microsoft.Exchange.2010.Mailbox.MdbOwningServerLocalEntityDiscoveryRule

    Instance name: x

    Instance ID: {67E25145-C9E8-9DF3-99F2-96F5058CADE1}

    Management group: PROD

  8. Rajiv says:


    Do you know the tentative ETA on Exchange 2010 SP1 MP?

  9. Ramesh says:

    Kevin – I used MPViewer to view the contents of this Exchange 2010 MP and exported it to xml. While opening it using XML notepad, I get the following error, but it opens using notepad:

    "Error loading: C:TempExch10.xml Name cannot begin with the '1' character, hexadecimal value 0x31. Line 863, position 130. Would you like to open it using notepad?

    It gives error "problems came up during load: Table" when opening thru excel. Just want to know if you too get this…

  10. Ramesh says:

    Thanks Kevin – That works! The Exchange 2010 SP1 MP should allow direct upgrade from Exchange 2010 RTM MP so we can retain our customizations/overrides – right? I know it would be the case, but wanted to double check

  11. uri says:


    i cant see the db size value empty.

    got any idea ?



  12. uri says:

    can i do somthing to see the db size ?

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