As most of Hosted Messaging and Collaboration (HMC) companies start planning to migrate to Exchange 2010 SP2 hosted environment due to the change in strategy that was announced about the future of /hosting mode here, so most HMC customer have to move directly to Exchange 2010 SP2 in hosted mode as discussed here, and one of the activities come up to migrate from HMC to Exchange 2010 SP2 is Downsizing activity in the running HMC environment to utilize part of hardware to be reused in the new Exchange 2010 SP2 environment, and although it looks like a simple activity for some IT people but there are a lot of challenges that can be in some cases for some specific HMC components show stopper to continue the downsizing activity, in this post series I will share all my experience with HMC downsizing activity and explain how I deal with different challenges in this activity, in Part1 I covered the first step of HMC downsizing activity to select server roles that will be decommissioned, then covered most of preparations tasks in each of the selected roles, and in Part2 I went through the most critical step of preparing Mailboxes for decommissioning that include the bulk mailbox move script that move mailboxes by calling MPS, one of the important resource while working in this activity is Microsoft Provisioning System SDK that can be downloaded from here.

In this post I will finalize this post series by finalizing 2nd Step of preparations and both 3rd Step for decommissioning activity itself and 4th Step which is post decommissioning activity.

So let me start with final preparations steps as follow:

  • If you run <QueryAllStore.xml> and still find some organizations assigned to any mailstore, then you should troubleshoot and find if there is any object (OU, User, Mailbox) that was removed in Active Directory and still existing in MPS and this object still allocated to one of mailstore in MBX server that you target for decommission, to solve this issue which is not easy to resolve there are different scenarios as follows:
    • Scenario1: If object was deleted by accident, then perform Active Directory Authoritative Restore as described here, and this option used only if the object deleted accidently.
    • Scneario2: deleted object not needed any more, then perform Database cleanup and then recreate the user if needed, to clean up the database you will need to know the GUID of the deleted object and this data can be retrieve from MPS SQL “PlanManager” with select statement like <Use PlanManager SELECT * from Customers>, once you get the GUID then you will need to run “DeleteCustomerByGUID” xml request (using provtest.exe)  to clean the MPS database from this object using the GUID you got using the SQL query..
  • Then you need to move the recovered mailbox from MBX server that is target for restore, and then to run <QueryAllStore.xml> again.

3rd Step: Now the environment should be ready for 3rd step which is the decommissioning or uninstall the selected server roles as listed in 1st step and it is recommended to do one more verification step before doing uninstall which is shutdown the target server role for certain amount of time and validate the the whole HMC solution still functional and provisioning still working without problems, then to uninstall role by role and give time between each one for testing and verify HMC environment functionality.

4th Step: which is the post decommissioning activities, and in this step you should use all available tools to verify the HMC functionality and solve any discovered issues (you need to confirm that there is an active Microsoft Support for the HMC environment that can be used in case you face any issue while decommissioning), as sample of these tools you can use the following:

  • Exchange Best Practices Analyzer
  • Exchange Connectivity Analyzer
  • OCS Connectivity Analyzer
  • Do some provisioning activities through the available control panel
  • Event Viewer

Hope that this post series can reducing the risk of downsizing activity and make it easier for consultant who will do the activity.

As a conclusion HMC downsizing activity need some planning and should be done carefully to avoid any risk that can affect the HMC production environment.

Related Posts:

Part1: http://blogs.technet.com/b/meamcs/archive/2012/11/11/downsizing-hmc-environment-to-prepare-for-exchange-2010-sp2-hosted-solution-part1.aspx 

Part2: http://blogs.technet.com/b/meamcs/archive/2012/11/12/downsizing-hmc-environment-to-prepare-for-exchange-2010-sp2-hosted-solution-part2.aspx 

Part3: http://blogs.technet.com/b/meamcs/archive/2012/11/19/downsizing-hmc-environment-to-prepare-for-exchange-2010-sp2-hosted-solution-part3.aspx