Disable DirSync - Perform cutover migration - Re-enable DirSync

Jorge Díez Tubet 31 Reputation points


I'm in the next migration scenario:
Company with on-prem AD connected through AD Connect to Microsoft365 Tenant.
They just adquired a company with no 365 but a Exchange 2010 environment.

They would want to migrate just the Exchage mailboxes to the main tenant, with no local AD unification, no AD connect synchronization. So a Cutover migration is what I expect is the best way to achieve it.

My concerns are that a cutover migration can't be performed while the tenant is DirSync enabled. So my guess is that if I disable it temporally, perform the cutover migration and re-enable it, I can incorporate to the 365 tenant this new 'cloud only' account without affecting what they previously had synced.
The previous Synced account will be converted temporally to Cloud only account, but login won't change, and once I re-enable sync, this accounts will match with the local accounts the same way they were.

Am I in a good planning or am I missing some key points.
I would highly appreciate any hints.

Thank you.

Microsoft Entra ID
Microsoft Entra ID
A Microsoft Entra identity service that provides identity management and access control capabilities. Replaces Azure Active Directory.
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Accepted answer
  1. Vasil Michev 98,676 Reputation points MVP

    The biggest issue is that the Cutover process uses its own provisioning workflow, and cannot leverage any existing accounts. It will error out if the account already exists. And, it provisions accounts based on the mail/windowsEmailAddress attribute, the "naming schema" is a bit different too, but that's usually not that big of a problem.

    1 person found this answer helpful.

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