**** 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:
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:
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: