Slow mailbox move with Exchange 2010 SP1


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:

 

RTM values:

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.

 

SP1 values:

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 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.

 

Don’t forget to restart the Microsoft Exchange Mailbox Replication service and do this configuration change on all your CAS servers

 

Comments (7)

  1. Anonymous says:

    Why was this changed?  Is this a bug? Can we expect a patch to change it back?

  2. sublemon says:

    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.

    communities.vmware.com/…/267925

    Which points to this article by Microsoft:

    support.microsoft.com/default.aspx

  3. Rachel says:

    Why do microsoft change the value down to 2? Any technichal considerations?

  4. jay says:

    Hi Sublemon,

    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.

  5. Joe says:

    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..

  6. johnredd says:

    Exchange 4, 5, 5.5, 2003 mailboxes/databases use single instance storage (SiS) to insert pointers (only store the body and attachments once) to files/emails/attachments within exchange 2k3 db Instead of having multiple copies of the same data object stored
    within the db.

    SiS is removed in ex2007, 2010, 2013.

    2k3 mailboxes that are taking advantage of SiS have to expand during mailbox moves to 2007, 2010 databases.

    http://blogs.technet.com/b/exchange/archive/2010/02/22/3409361.aspx

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