none
Migrating from Exchange 2013 to Office 365 RRS feed

  • Question

  • Hi Guys,

    I have 2 on-premise servers running exchange 2013 server roles. I just subscribed to Office 365 E3 plan and have setup directory sync on one of my AD servers. Now I intend to migrate mailboxes to office 365 and decommission the on-premise exchange servers.

    What are my options for doing this? Must I configure exchange hybrid before I can accomplish this? I really would not want to go through the hassle of setting up a hybrid deployment specially since the on-premise exchnage servers will be retired once the migration is completed.

    Appreciate your advise and references like always.

    Cheers .. 

    ..forever is just a minute away*

    Wednesday, May 4, 2016 1:16 PM

Answers

All replies

  • Hybrid will give you the best experience, but might be an overkill for small organizations. You can use Cutover migration, but you have to disable dirsync first (and probably do a cleanup of the already synced users). PST Import/Export or using 3rd party tools are your other options as discussed here: https://support.office.com/en-us/article/Ways-to-migrate-multiple-email-accounts-to-Office-365-0a4913fe-60fb-498f-9155-a86516418842?ui=en-US&rs=en-US&ad=US

    Note that if you plan to keep dirsync for management purposes after the migration, you need to keep at least one on-prem Exchange box for management purposes. This is detailed in the following article and it applies to both Hybrid and dirsync-only: https://technet.microsoft.com/en-us/library/dn931280(v=exchg.150).aspx

    Wednesday, May 4, 2016 7:01 PM
  • Hello,

    When you require directory sync from your on-premises AD to Azure AD, you cannot use Cutover Migration. You can do:

    1. Hybrid Deployment and Remote Move Migrations - overkill for small organizations.

    2. IMAP Migration - moves only emails, no calendars, no tasks etc but sometimes it can be useful.

    3. 3rd Party Tools like http://www.codetwo.com/office-365-migration/.

    4. PST Export/Import.

    As Vasil wrote, after migration you should have one Exchange server for management purposes.


    My LinkedIn profile

    Wednesday, May 4, 2016 7:15 PM
  • Hey Richard,

    A staged migration is only available for 2007 and earlier so that is ruled out. 

    A cutover migration is only available for less than 2000 objects and is ruled out once you enable directory synchronization. Although it can be enabled after a migration is complete. 

    Once you configure directory synchronization your on-premises Active Directory becomes the source of authority for all cloud objects. That said you can manage your cloud based object in two ways. Through the use of a hybrid on-prem Exchange server (supported) or through another tool such as ADSI Edit or 3rd party (unsupported).

    You don't need to maintain two servers. You could drop it down to one and could potentially even size it down to the minimum requirements depending on the user load. Although keeping two servers is useful for HA if you plan to keep Exchange around for other tasks such as an internal SMTP relay, or, do decide to keep some mailboxes on-prem.

    If you plan to go for an unsupported method of management going forward you can either use a hybrid configuration to migrate, or, go with a 3rd party tool to do the migration.


    Practical help for Exchange & Office 365 - SuperTekBoy | Twitter | LinkedIn

    Wednesday, May 4, 2016 8:43 PM
  • Hi Guys,

    I have 2 on-premise servers running exchange 2013 server roles. I just subscribed to Office 365 E3 plan and have setup directory sync on one of my AD servers. Now I intend to migrate mailboxes to office 365 and decommission the on-premise exchange servers.

    What are my options for doing this? Must I configure exchange hybrid before I can accomplish this? I really would not want to go through the hassle of setting up a hybrid deployment specially since the on-premise exchnage servers will be retired once the migration is completed.

    Appreciate your advise and references like always.

    Cheers .. 


    ..forever is just a minute away*

    You need to have Hybrid setup while you move to O365 and then later you decor your on-prem if you think you don't them and everything works from from O365.

    Yes Install the DirSync and Activate it on O365 Tenant. Run the HCW and make the necessary configuration and start migrating the mailboxes.


    Where Technology Meets Talent

    Thursday, May 5, 2016 1:31 AM
  • Hi,

    I have found the following article which introduces the detailed information about migration from exchange server to office 365:

    https://support.office.com/en-us/article/Ways-to-migrate-multiple-email-accounts-to-Office-365-0a4913fe-60fb-498f-9155-a86516418842

    In addiction,I suggest we have at least one Exchange Server on-premises to manage. When directory synchronization is enabled for a tenant and a user is synchronized from on-premises, most of the attributes cannot be managed from Exchange Online and must be managed from on-premises. So

    Please have a look at the following blog to get more detailed information:

    https://blogs.msdn.microsoft.com/vilath/2015/05/25/office-365-and-dirsync-why-should-you-have-at-least-one-exchange-server-on-premises/

    Regards,

    David


    Thursday, May 5, 2016 6:27 AM
    Moderator
  • Hi Guys,

    Thanks for the inputs and advise.

    So if i get this right, it means to have DirectorySync/SSO work properly, I have to leave an exchange server on-premise?

    And if I choose to do a cut over migration then i cannot have DirectorySync/SSO?

    Looks like my client has to sacrifice the option of DirectorySync/SSO as they are not willing to keep any server in-house.


    ..forever is just a minute away*

    Thursday, May 5, 2016 9:41 AM
  • I'm not sure how this sounds but 

    what if I break the existing DirSync and perform a cut-over migration, decommission the on-premise exchange servers and then configure DirSync for SSO ..will I still require an on-premise exchange server to manage mailboxes online?


    ..forever is just a minute away*


    Thursday, May 5, 2016 10:10 AM
  • Any configuration in which you have Dirsync involved in managing synced accounts will require you to keep at least one Exchange box, IF you want to stay in supported scenario. If you are fine with managing attributes via PowerShell/ADUC/ADSI Edit or any other tool, and if you are fine with the possibility of Microsoft denying you support in case something happens, you can decommission the Exchange servers. As lots of organizations have done, the important part is that you need a clear understanding of what this all means.

    As for the actual migration, yes, you can do a Cutover if you disable dirsync. But you will probably need to do some cleanup. Dirsync provisions accounts based on the value of UPN/samaccountname attributes, while the Cutover process uses WindowsEmailAddress. If those match for your users, you will be fine. If they don't match, the Cutover process will fail, complaining that an object already exists.

    Or you can go with PST export/import or 3rd party tools.

    Thursday, May 5, 2016 11:52 AM
  • Thanks Vasil,

    one last query if you dont mind. Some of my colleagues are of the opinion that if I have ADFS setup with DirSync then I do not need to keep an exchange server on-premise. Is this correct?

    If the above is not correct then I will go ahead and retain one exchange server on premise and setup only DirSync.

    I plan to begin the migration process next week and want to be clear on all the options while remaining in a supported configuration.r

    Also, I have verified my domain so the internal domain matches the domain on O365. Does this affect federation in any way? My idea of federation is the integration of two different organisations for trust ..seeing that both on-premise and O365 are same I am confused as to how that ‎will work.

    Thanks for all the help guys ..


    ..forever is just a minute away*

    Friday, May 6, 2016 2:08 PM
  • https://msdn.microsoft.com/en-us/library/bb897402.aspx?f=255&MSPPError=-2147217396

    ADFS is for Single Sign On (SSO)

    DirSync is for password Sync only.

    choice is yours


    Where Technology Meets Talent

    Friday, May 6, 2016 2:52 PM
  • you keep one or the other

    Where Technology Meets Talent

    Friday, May 6, 2016 2:52 PM
  • Any configuration that involves managing Exchange related attributes on-prem requires you to have an Exchange box, if you want to stay in supported scenario. Including situations such as migrating from Lotus Notes or other 3rd party solutions.

    Again, it's not mandatory to keep the box, a lot of companies just ignore the official guidance. But it's out duty to warn you about it, the decision is yours of course :)

    As for federation, you are confusing the two terms. Exchange federation is used for sharing free/busy info between two organizations, or GAL, photos, etc. AD FS federation on the other hand is the process of redirecting the login process to your on-prem servers, which O365 will 'trust' as the source of authority for any federated domains. In the case of O365, both features require dirsync.

    Friday, May 6, 2016 3:29 PM
  • Hi Guys,

    I have 2 on-premise servers running exchange 2013 server roles. I just subscribed to Office 365 E3 plan and have setup directory sync on one of my AD servers. Now I intend to migrate mailboxes to office 365 and decommission the on-premise exchange servers.

    What are my options for doing this? Must I configure exchange hybrid before I can accomplish this? I really would not want to go through the hassle of setting up a hybrid deployment specially since the on-premise exchnage servers will be retired once the migration is completed.

    Appreciate your advise and references like always.

    Cheers .. 

    ..forever is just a minute away*

    You must configure the DirSync to achieve this. I don't why this thread has gone to ADFS

    check this MVA video and jump directly to the DirSync implementation

    If you have more than 50 users then let microsoft do  it for using Fast Track

    https://mva.microsoft.com/en-US/training-courses/managing-office-365-identities-and-services-8303?l=cMt7TjYy_7104984382


    Where Technology Meets Talent

    Friday, May 6, 2016 3:38 PM
  • I would like to add Microsoft Exchange Server deployment assistant.

    It is free guide from Microsoft team.

    It asks few questions about your current environment and further, provide you step-wise instructions by checking all necessary prerequisites.

    Here you go https://technet.microsoft.com/en-us/exdeploy2013/Checklist.aspx?state=3229-W-AAAAAAAAQAAAAAEAAAAAAAAAAAAAwAMAAAA%7e

    Friday, July 5, 2019 11:54 AM