#Preparation

Before the migration, you need to think about what object types they want to migrate. Refer to the Supported and Unsupported List.

#1. Create a service account or app profile with required permissions

To connect Fly to your Groups, create a service account or an app profile with the required permissions in AvePoint Online Services. In general, you need to grant the following required permissions to the service account before the migration:

• Group Owner and Member

• Mail Recipients roles

• License for Exchange Online

Refer to Required Permissions to check the required permissions for Microsoft 365 Groups to Microsoft 365 Groups Migration.

#2. Run the source tenant discovery (optional)

Before you migrate from Microsoft 365 Groups, you can run a tenant discovery of Microsoft 365 Groups to scan and report the object count, object type, object size, and other details. According to the discovery reports, you can better understand your source environment and plan for your migrations. Refer to the user guide for Tenant Discovery for details.

#3. Create users in destination tenant or sync AD users

User mappings are required when executing migrations. Make sure users of the following data are created in the destination tenant before the migration.

• Group Membership

• Task: Assign To

• Mail: To, Cc, Bcc, Senders, etc.

• File: Modified by, Created By, Shared link

• Permission

• Other data that needs users

Refer to the user guide about how to prepare users.

#4. Assign license to users

If you want Fly to assign the Group Owner role to destination users in the migration, the users must have Microsoft 365 licenses. We recommend that you assign Microsoft 365 licenses to all destination users for easy use. 

#5. External users

External users cannot be migrated in the migration. You can export external users and import them into the destination tenant prior to the migration.

Refer to the following steps to export external users and import them into the destination tenant:

1. Make sure you have the Azure AD PowerShell Module installed before running the scripts. See instructions here.

2. Run the PowerShell script to export the external users from the source tenant to a CSV file. (You can click the link to download the script.)

3. Run the PowerShell script to import the users in the CSV file to the destination tenant. (You can click the link to download the script.)

#6. Create Groups in destination tenant (optional)

Fly can create Groups in the destination with the default domain of the destination tenant. If you want to create Groups without the default domain of the destination tenant, or you want to migrate to existing Groups, you can create Groups in the destination before the migration.

#7. Handle large mail items for migration to destination mailboxes

Microsoft sets a default limit of 35 MB as the maximum size of a received message. We recommend increasing this to 150 MB before the migration to avoid any potential exceptions. Refer to larger email messages to configure the limit.

Sample PowerShell command:

Set-unifiedGroup -Identity group@contoso.com -MaxReceiveSize 150 MB

#8. Check destination retention policies

If retention policies are configured for the source data, check to make sure the destination retention policies are the same as the source retention policies. Otherwise, the destination data may be deleted due to different retention policies.

#9. Throttling limits

Microsoft uses throttling to manage Microsoft 365 operations and throttling limits will affect migration performance. Go to the Microsoft 365 admin center to lift the throttling restrictions.

1. Go to the Help (?) section of the Microsoft 365 admin center.

2. Enter EWS throttling as the search phrase.

3. Click Run Tests when you are asked to check your environment. Essentially, the tests check what EWS throttling applies to the tenant.

   

4. The support assistant checks the tenant settings and concludes that EWS is throttled (the normal situation). You will then be offered the chance to update the settings to the tenant EWS policy to lift throttling for 30, 60, or 90 days.

5. Select the number of days to adjust the policy, and then click Update Settings.

   

6. After a short delay, the support assistant will confirm that the settings have been changed.

#10. Prepare sensitivity labels in destination (optional)

If the source tenant does not have sensitivity labels, you can ignore this step.

If the source tenant has sensitivity labels, and you want to keep the source sensitivity labels applied on Groups/emails/files to the destination, you need to create and publish the sensitivity labels in the destination before the migration. Refer to Create and publish sensitivity labels for details.

#11. Create source and destination connections

Refer to Create a Connection to connect Fly to your source and destination Groups. The connection including both the app profile and service account is recommended.

#12. Migration throughput

In Microsoft 365 Groups to Microsoft 365 Groups migrations, the job speed depends on the size of SharePoint team sites and the size of Group mailboxes.

SharePoint Site Migration Throughput

Generally, a reasonable SharePoint site migration speed is about 2 GB/hour/mapping. The number of mappings that run in parallel is automatically allocated based on your purchased subscription. The more subscriptions you purchase, the more mappings you can run in parallel.

Mailbox Migration Throughput

Generally, a reasonable migration speed of the mailbox is 1.5 GB/hour/mapping. The number of mappings that run in parallel is automatically allocated based on your purchased subscription. The more subscriptions you purchase, the more mappings you can run in parallel.

We can calculate how much content can be migrated with the above infrastructure.

There are many factors which may affect the migration performance:

• The above throughput number is for the full migration. Generally, it may be lower for the incremental migration since Fly needs to spend quite some time checking the migrated items’ status for the incremental migration.

• The above results are only ideal values after many tests. The migration speed of different tenants may be different. We recommend that you estimate the daily throughput in the same way as the results of the pilot job.

• If your Planner is particularly large, the overall migration speed may be slowed down.

#13. Prepare mapping files

Configure Groups mapping files and user mapping files: 

• Examples in the Group mapping file

  

• Examples in the user mapping file 

  

#14. Design the migration policy

A Microsoft 365 Groups to Microsoft 365 Groups migration policy allows you to define the migration scope of group objects, the conflict resolutions, whether to replace source email addresses/meeting links with destination, how to map users, and how to manage the sensitivity labels of files/emails/Groups for Microsoft 365 Groups to Microsoft 365 Groups migrations. Refer to Create a Migration Policy for details.

#15. Understand when destination users will receive notifications

In some situations, destination users will receive email notifications when they are added to destination Groups or source objects are migrated to destination users.

#Full/Incremental migration job

The table below shows specific situations when destination users will be notified.

#Migrate membership job

The table below shows specific situations when destination users will be notified.

#Disable welcome emails (optional)

Generally, users will receive welcome emails if they are added as members of a Microsoft 365 Group. If the destination Groups are newly created by Fly in the migration, Fly will disable the welcome emails by default to avoid interruption. However, if the destination Groups already exist before the migration, Fly will not disable the welcome emails. You can manually disable the welcome emails.

Refer to the following steps to disable or enable the welcome emails:

1. Install the Exchange Online PowerShell V3 module to the server where you will run the DisableAndEnableGroupWelcomeEmail.ps1 file. Refer to Install Exchange Online PowerShell V3 module for details.

2. Connect the Exchange Online PowerShell V3 module to Exchange Online. Refer to Connect to Exchange Online for details

3. Download the GroupWelcomeEmail.zip, and extract the ZIP file to a location with a network connection.

4. In the extracted tool folder, open the Template.csv file, and configure the email addresses of Groups for which you want to disable welcome emails.

5. Right-click the DisableAndEnableGroupWelcomeEmail.ps1 application file, and select Run with PowerShell.

6. Enter your credentials, and click OK to open the PowerShell window.

7. Enter the full path of the CSV file configured in step 4, and press Enter on the keyboard.

8. To disable the notifications, enter option 1 and press Enter on the keyboard.

   To enable the notifications, enter option 2 and press Enter on the keyboard.

#16. Plan a pilot run

We recommend you perform a pilot run for the following purposes:

• Get familiar with the Fly interface and understand the whole migration process.

• Discover any potential issues early and resolve them before production migration.

• Understand the throttling situation in case content size is large, and then try to resolve with destination.