Best way to do a phased tenant to tenant migration

The phased migration approach involves migrating selected users and workloads across multiple cutover events.

If you have a large user base or overall data size, a staged migration may be the better option. It will provide you with the flexibility needed to break the migration into batches, allowing you to migrate selected users or workloads individually. For example, schedule the migration of the Exchange workload for one weekend and the SharePoint or OneDrive workload for the next.

This approach has the following advantages:

• Lower overall risk as only specific workloads or groups of users are migrated at a time
• Provides greater flexibility
• Batches can be organised so that the amount of data migrated is manageable within the cutover window
• If any issues are encountered during the migration process, such as transfer throttling, it’s possible to mitigate and plan around these issues for the migration of future workloads
• This approach has the following disadvantages:
• Users will often require duplicate licensing across the source and destination environments for extended durations
• Requires more planning and communication due to added complexity
• Users will need to sign-in with multiple identities for a period of time if you opt to batch by workload
• There may be limitations on what can be done in the destination environment until the migration is fully complete

Hi @Cory Calavan

Here is a Microsoft documentation which provides a overview of this process.

For your reference: Microsoft 365 tenant-to-tenant migrations

Detailed information can be found in the Tenant-to-tenant migration architecture model pdf.

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Hi,

correct that it is possible to transfer a subscription from one tenant to another, which will transfer all of the resources associated with that subscription to the new tenant. This is known as a subscription transfer, and it can be a simpler option than a tenant-to-tenant migration if you only need to move a single subscription and its associated resources. However, there are some limitations and considerations to keep in mind when using this method:

• The subscription must be in the same billing account as the destination tenant.
• All resources in the subscription must be in the same region as the destination tenant.
• The subscription must not be in a suspended or deleted state.
• You will lose access to the subscription in the source tenant after the transfer is complete.
• Any resource locks or policies that are applied to the subscription will be removed.

To perform a subscription transfer, you will need to use the Azure Portal, Azure PowerShell, or Azure CLI. The process involves specifying the subscription and tenant to transfer from and to, and then confirming the transfer.

If you want to move multiple subscriptions or resources that are not associated with a subscription, or if you want to move resources across multiple tenants, then a tenant-to-tenant migration is required. This can be a more complex process and requires more planning and effort, but it provides more flexibility and control over the migration process. There are different ways to perform a tenant-to-tenant migration, such as using Azure Backup, Azure Site Recovery, or Azure Migrate, and each method has its own set of requirements and limitations. PowerShell scripting can be used to automate some of the tasks and simplify the process.

It's important to note that, regardless of the migration method you choose, you should have a solid backup strategy in place before and during the migration to ensure that you can recover your data in case of any issues.

cheers!.