A migration between Exchange Server and Office 365 is considered completed after all the messages from the source mailbox are transferred to the destination mailbox. It is called syncing, and when the batch migration is in the final stages, then it denotes its status as syncing. But in some cases when the size of the mailbox is too large, or the receiving Office 365 mailbox does not have proper permissions, then syncing is stalled and the migration will be stuck for an unlimited period.

You can view the status of the mailboxes migration batches in the Exchange Admin Center which is still syncing and none of the mailboxes has migrated yet.

As you can see in the above image, even after the considerate time of starting the migration batch, the status is Syncing, and under the Mailbox status, zero mailboxes have been synced from the total four in the batch. You can click on View details to check it in detail. It shows that the migration has been stuck and this situation requires a solution.

If you have faced such a problem earlier, then you may be aware of the struggle to complete the migration. But here is a solution that you can follow and resume a stuck migration request.

Read Also : How Small Organizations Can Migrate Exchange Mailboxes to Office 365?

First, you should know the actual status of the migration by running the following command –

After it shows the status as Syncing, then OK. But if it shows the status as Queued for a very long time, then you need to troubleshoot the problem.

1. There is a possibility that Exchange Server does not have ‘ContentSubmitters’ Security Group, which is necessary for placing the data. So, you need to create it at the Active Directory by following the upcoming steps –
   • In Active Directory, right-click on the folder where you want to create the security group, click New, and then choose Group.
   • Provide the name ‘ContentSubmitters’ and select the Group Type as ‘Security.’
   • In the Active Directory, go to the View tab and check the Advanced Features.
   • Now go to the ContentSubmitters group, right-click and select Properties. Here, under the Security tab, see if the Administrators Group has the Full Control option checked. Check it and click, OK.
   • Click the Add button and input the name ‘Network Service,’ then click OK.
   • Provide Full control to the newly created group Network Service.
   • Finally, restart the two Exchange Services – Microsoft Exchange Search and Microsoft Exchange Search Host Controller.

   Now, go to Exchange Management Shell and run the same command –

   Get-MoveRequest | Get-MoveRequestStatistics

   Now the status of the migration batch should be changed to Syncing or any other stage of migration.

2. If the status of the migration shows that ‘StalledDuetoCI,’ then it is an issue which you need to rectify.

   The CI means Content Indexing, and you need to turn it off for the respective mailbox database until the migration is complete.

   To get the complete name of the database, go to Exchange Admin Center and check the databases tab. Here, selects the database for which you are conducting the migration. Then go to database copies and get the complete name of the database.

   Now go to Exchange Management Shell and run the command –

   Set-MailboxDatabase “MailboxDatabase12345” -IndexEnabled:$False

   After running the command successfully, restart the Exchange services like Microsoft Exchange Search, Microsoft Exchange Search Host Controller, and Microsoft Exchange Mailbox Replication.

   Now recheck the status of the migration.

   Get-MoveRequest | Get-MoveRequestStatistics

   The status of the migration should be changed to Migrating or Syncing. But keep in mind that after successful completion of the migration, you need to enable content indexing.

   Set-MailboxDatabase “MailboxDatabase12345” -IndexEnabled:$True

   By using the troubleshooting methods mentioned here, you will be able to resolve the Office 365 migration stuck on syncing/completing the issue effectively.

Conclusion

It is common that organizations face unexpected issues during Exchange to Office 365 migrations. Shortage of physical resources, lack of expert supervision, unavailability of professional migration tools, etc. are some of the reasons for Exchange to Office 365 migration issues. By using professional Office 365 Migration tool like Kernel Office 365 Migration, many of these issues can be foreseen and avoided. Also, this tool helps in automating many migration tasks.