Increasing the number of simultaneous Remote/Local Move Request on Exchange 2010

By default Exchange 2010 just move 5 mailboxes simultaneously, it can make a migration of about 1500 mailboxes take 3 or more days.


To increase it you have to change a configuration file for Mailbox Replication Service. 


1. Open the file C:\Program Files\Microsoft\Exchange Server\V14\Bin\MSExchangeMailboxReplication.exe.config;
2. Increase the blue values to a number of simultaneous active moves that you want.

MRSConfiguration
    MaxRetries = "60"
    RetryDelay = "00:00:30"
    MaxMoveHistoryLength = "2" 
    MaxActiveMovesPerSourceMDB = "50"
    MaxActiveMovesPerTargetMDB = "50"
    MaxActiveMovesPerSourceServer = "50"
    MaxActiveMovesPerTargetServer = "50"
    MaxTotalMovesPerMRS = "100"
    FullScanMoveJobsPollingPeriod = "00:10:00"
    MinimumTimeBeforePickingJobsFromSameDatabase = "00:00:04"
    ServerCountsNotOlderThan = "00:10:00"
    MRSAbandonedMoveJobDetectionTime = "01:00:00"
    BackoffIntervalForProxyConnectionLimitReached = "00:30:00"
    DataGuaranteeCheckPeriod = "00:05:00"
    EnableDataGuaranteeCheck = "true"
    DisableMrsProxyCompression = "false"
    DisableMrsProxyBuffering = "false"
    MinBatchSize = "100"
    MinBatchSizeKB = "256" ;

3. Save and close the file;
4. Restart the Microsoft Exchange Mailbox Replication service.

I've used the above configuration to migrate about 1400 mailboxes (its average size was 200MB) and it took 12hs to finish, using gigabit ethernet.