I had complaints from some of my customers that moving users to Exchange 2010 SP1 system is slow and taking long time. In RTM Exchange was doing 5 parallel moves at a time due to the following settings:
MaxActiveMovesPerSourceMDB: This property indicates the number of mailboxes that can be moved on the source mailbox database at one time. The default value is 5 concurrent moves.
MaxActiveMovesPerTargetMDB: This property indicates the number of mailbox moves that can be moved on the target mailbox database at one time. The default value is 5 concurrent moves.
MaxActiveMovesPerTargetMDB: This property indicates the number of mailbox moves that can be moved on the target mailbox database at one time. The default value is 2 concurrent moves.
The change in MaxActiveMovesPerTargetMDB in SP1 means that we can only do 2 concurrent connections.
The workaround: check the values in the following file “Exchange Server\V14\Bin\MSExchangeMailboxReplication.exe.config” and you can change MaxActiveMovesPerTargetMDB back to 5 to allow 5 concurrent moves.
and you can change
Don’t forget to restart the Microsoft Exchange Mailbox Replication service and do this configuration change on all your CAS servers
Why was this changed? Is this a bug? Can we expect a patch to change it back?
For those who are moving mailboxes from your physical server to a server hosted on VMServer on the same box, you might be suffering from what I was. The move was so painfully slow that I was blaming it on the MRS. 45% in 2 days and 13 hours!
I eventually tried to copy the file manually and found I was getting 16KB/sec! I did some research and ran into this article on the VMware communities. Once I made the change, I was able to move my 2GB mailbox in about 30 minutes.
Which points to this article by Microsoft:
Why do microsoft change the value down to 2? Any technichal considerations?
Did you install the hotfix to fix it? install the hostfix on the cas/hub and mailbox server(cas/hub and mailbox are on the seperate servers)?
Thank you and looking forward to your answer.
I think this change is really badly thought through. Unless I am missing something any batch mailbox moves I do will use this setting now (2 mailboxes at a time - not 5) and to resolve it I need to stop the mailbox moves and then ON EACH CAS server in My organization I need to edit a config file and restart a service? Crazy..
I have tried putting this as an article