Migration Manager for Active Directory

Dell Migration Manager 8.14 for exchange - Outlook slow

Issue noticed : Users complain that outlook is sluggish / status shows disconnected at random intervals

On investigation it was found that the users were part of migration batch and the migration copy process is causing this issue

Users are using outlook in online mode (VDI ) and also users are using cached exchange mode in laptops.

On exchange servers we notice lsass process is using high cpu.

Could you please advise any hotfix which can resolve this issue or is this a known issue.

Then we can schedule migration only during off business hours.

Exchange server OS : Windows 2012 R2

Exchange version : 2013 CU15

Outlook 2010 SP2

Thank you


  • Hello Luke,

    We have now shutdown the migration servers and no calls reported till now.

    Also ref the release notes and see comment

    Users will not be able to use Microsoft Outlook to log on to their mailboxes while the Mail Source Agent is processing them within a Remote Users Collection. If a user is working online, Microsoft Outlook will not operate while the mailbox is being processed. After mailbox processing has been completed, a user must log off and log back on to the mailbox.


  • Ajit,

    Are you using Remote User Collections? (RUC) What is your source & target Exchange versions, because it's not likely that you would be using a RUC in this day as they are only available using the legacy Mail processing agents, and that's not very common these days.

    It's true, if you were, that's expected behaviour, and your processing of these mailboxes, if done with a RUC, should be done off hours.

  • My apologies, I did missunderstand that the users are "Currently" in a migration batch.

    I can understand that if the mail agents are running, that your environment will see some impact, there isn't much we can do about that. The Disks/Attached storage will see lots of usage, along with other resources in your exchange environment. This is somewhat expected during processing.

    You may wish to not process so many mailboxes at once if the environment cannot handle the impact. Perhaps disable a collection, and see if this helps.

    Per below though, if you are using RUCs, then the users cannot be logged into their mailboxes. It will absolutely cut them off/block access.

  • Hello,

    Sorry to interject here, where does it say in the documentation that the RUC is supported with EX 2013 using Legacy clients? Only Migration Agent for Exchange (Mage) can be used.

    The only agents that preserve the OST file in Outlook outside of the Legacy mail source and mail target agents that preserve OST files is the Native move.