Some user on Migration Job is stuck failed "Couldn't switch the mailbox into Sync Source mode" RRS feed

  • Question

  • My environment have 4 exchange server in 2 active directory sites.

    • HQ Site have 2 exchange server 
    1. CAS01 - Client Access and mailbox role -> this server is primary client access, all DNS record such as autodiscover pointed to this server
    2. MB01 - Mailbox Role
    • Datacenter Site have 2 exchange server  (one server acting Client Access role and one server for mailbox role)
      1. CAS03  - Client Access role
      2. MB02 - Mailbox Role

    All exchange server is Exchange 2013CU23.

    I've two mailbox database in one database availability  group on "MB01" and "MB02" server.

    We have setup exchange hybrid on the "CAS01" server. 

    I've created multiple migration job with multiple user in job, On the first run the migration job can synchronize to 95% and status is shown "Synced", after several day the job still can incremental sync. But some user in migration job can't sync. The error message is below

    Couldn't switch the mailbox into Sync Source mode. This could be because another administrator is currently moving the mailbox into the destination database, the mailbox is locked, or the Microsoft Exchange Mailbox Replication service doesn't have the correct permissions. FailureType: SourceMailboxAlreadyBeingMovedTransientException.

    I followed change a setting the KeepAliveTime on the server the source mailbox to 5 minutes. But the error message is still. Please advice me. Thanks

    Microsoft Docs: https://docs.microsoft.com/en-us/archive/blogs/brad_hughes/source-mailbox-already-being-moved-errors-while-moving-mailboxes

    Monday, August 24, 2020 7:34 AM