Teams Channel Cross Tenant Migration
Starting with the generics of Teams Team/ Channel migrations. There can be not Team without a corresponding M365 group. This implies, that other services are available and Teams is heavily depending on those. Mainly it is SPO/ OneDrive. It is used for files in Teams.
Not talking about the M365 Group provisioning here in detail, but the important sequence you must follow is:
1. Create a user mapping file and provision target users
2. Provision M365 groups in target tenant
all member user must exist
Note for M365 Groups:
There is no tool available yet, which could keep M365 Groups in persistent sync. Therefore, delta sync’s are required.
Other services used by or from within Teams are e.g. Tabs, Wiki & Planner. Shared Mailbox are not part of the Teams integration, but other apps made available in Teams might.
Secondly, Teams has shared channels and private channels. Both have their own complexity.
· Private channel require a Teams “hull” provisioning and cannot be delta provisioned.
· Shared Channels required a user mapping source to
target for Guest User
Guest User must be provisioned before the provisioning and migration starts
(Note: at the point of writing this article, shared channels are in public preview)
Let’s talk about a “hull”
provisioning. After M365 Groups are copied, the process of provisioning services
starts. A Teams hull, consist of the readiness of SharePoint Online, OneDrive
and Site, further the entire Channels in Teams. This is the structure only,
without any content.
It is advised before doing any content migration, ensure the especially for PRIVAT and SHARED Channels, the structure “hull” is re-provisioned/ copied again.
Than a FREEZE must be applied, because any changes to the private channel (memberships) will not be reflected.
It is not required using a single migration tool for this holistic process, rather it could be segregated into different tools. Only for the provisioning incl. the involved users, it is recommended doing it with the same tool.
You can even use different tool for say, SharePoint sites and OneDrive. You have to evaluate the content making the right decision with set of tool will support you best and which method you could apply for those service and reuse them from other migration tasks.
The other important topic is, that OneDrive must be provisioned and migrated before you can migrate chats into the channel. Messages might contain documents shared, those files you will find in ODB. Applying the shared permissions again, and further LINKING the file to the chat message require those to be present in the target already.
Sequence for Teams Team migration (Team/ Channel)
1. Provision users and guest users in target
2. Have user mapping file ready and complete
3. Provision the M365 Groups in target
4. Synchronize the Teams “HULL”/ structure incl. private/
5. Start content migration for OneDrive, SharePoint and Mailbox (pre-load)
6. REPEAT: Provision the M365 Groups in target
7. REPEAT: Synchronize
the Teams “HULL”/ structure incl. private/ shared channels
8. Freeze source Teams Team and services assigned along
9. Initiate final migration of all service (at least ODB, SPO)
10. Start Chat Migration / Channel