Forum Discussion
O365 Email Migration to Another Tenant while Deferring Migration of Sharepoint files
Hi,
This is the context: ChildCompany has O365 and it has an Azure AD in hybrid mode synchronizing to a on-prem AD server. They have an internal domain ChildCompany.com, and an external domain ChildCompany.com where they also receive and send email using O365.
ParentCompany is going absorb the ChildCompany some time in next year, and I was asked about the integration options.
According to this https://download.microsoft.com/download/b/a/1/ba19dfe7-96e2-4983-8783-4dcff9cebe7b/microsoft-365-tenant-to-tenant-migration.pdf
I could do a phased migration, where the end state is that they decomm their onprem AD and that they only use our ParentCompany systems.
The business requirement is to start their integration with Email, and then in later phases do the Sharepoint integration as that requires way more analysis on their data sources, as they also have wikis and many other on prem legacy stuff.
They are less than 50 users, so I can use Quest migration tools for the email part, but I wonder what needs to happen in what order.
This is what I have in mind:
Migrate their current O365 into our ParentCompany Office 365 subscription, so that they can continue logging in into their domain joined windows machines using childCompany.co, so they start using ParentCompany.com email addresses, but the problem then is how can they continue using their sharepoint and onedrive resources associated with the Azure and local domain at ChildCompany.com?
This is more or less what I have in mind, for the intermediate step, the cutover:
Child Company ParentCompany
--------------------- ----------------
On-Prem | MS Cloud: | MS Cloud:
---------------|----------------------|--------------
Local AD (ADFS)| Azure Subscription | Azure Sub
| Azure AD | Azure AD
|--------------------- |---------------------
| O365 Sub -> | O365 Sub
| Exchange mailboxes-> | Exchange mailboxes
| Sharepoint? -> | ???
| -------------------- |---------------------
I wonder how could it be possible to defer the sharepoint and onedrive migration, so that the child company users can still work on their sharepoint files using their normal auth methods, while disabling childcompany.com as MX so they start using ParentCompany.com mailboxes.Is that even possible? Would make more sense to try to migrate everything at once? That is way more work, but I'm weighting my options.
- For just 50 users, you should be able to migrate all the content over the course of a single weekend, even if doing things manually. There is no requirement to move everything at once, but it's certainly the easier option. If you settle on phased approach, users will have to leverage two sets of credentials, as you cannot share the same domain name across multiple tenants.
- So, in principle, could it be done that way? I changed the numbers a bit (so the post would not be easily identifiable), but the truth is that it can not be done in only one stop weekend. It needs to happen in phases, as there is a separation between resources allocated to do the email and sharepoint migration (which is way too much for only one person).
- As mentioned above, there is no requirement to move all the content at once. We've had migrations that run for weeks/months, but that usually complicates things as you need some form of co-existence. You might as well consider third-party offers, as they usually streamline most of the process.
You can have better handle by Quest, see below URL:
- Thanks for answering, but that is unhelpful. I want to read and document myself on what it implies, not getting a consultant do it for me.
Do you have links on coexistence strategies and its implementations, the info I've found is scattered and too high level. The problem is what happens when the domain is transferred, and I still want to access the child company O365 apps using some auth method, I dunno like using onmicrosoft.com or something.
