Fix Hybrid Exchange Mailbox Migration Stuck in Completing State
Question details
An Exchange hybrid mailbox migration remains stuck in the 'Completing' state for several hours.
- Product
- Microsoft Exchange
- Device & OS
- not provided
- Scenario
- Moving a large on-premises mailbox (approximately 48.9 GB) to Exchange Online within a hybrid deployment configuration.
- Observed behavior
- The migration request hangs indefinitely at the 'Completing' stage and does not finalize the move to Exchange Online.
Ensure you have the necessary Exchange administrator permissions and access to the Exchange Management Shell before running diagnostic commands on the affected mailbox.
Diagnose Move Request Statistics via Exchange Management Shell
Generate a detailed XML report of the move request statistics to identify the root cause of the stalled migration.
Large mailboxes, such as those around 50 GB, can sometimes experience delays during the final synchronization phase. By exporting the move request statistics, you can pinpoint whether the delay is due to bad items, network constraints, or a backend Exchange Online throttle.
Confirm that the mailbox is specifically being moved from the on-premises Exchange server to Exchange Online, as troubleshooting steps may differ for reverse migrations.
Navigate to the Exchange Admin Center (EAC) > Migration tab. Select the affected migration batch and click 'View details' to check for any visible error messages or bad item counts.
Open the Exchange Management Shell and execute the following cmdlet to gather advanced diagnostic data: Get-MoveRequestStatistics -Identity 'UserMailbox' -IncludeReport -DiagnosticInfo showtimeslots | Export-Clixml -Path C:\Temp\MoveReport.xml
Review the exported XML file for specific failure codes. Additionally, verify your exact Exchange Server version, check if other mailboxes in the batch are affected, and confirm whether your deployment uses a full or minimal hybrid configuration.
Maintain Productivity During IT Migrations with WPS Office
While your IT team resolves Exchange server and email migration issues, ensure your organization's daily document work remains uninterrupted. WPS Office provides a lightweight, highly compatible, and free alternative to Microsoft Office.
- 1. Download the software: Visit the official WPS Office website and download the installer for your operating system.
- 2. Install and launch: Run the lightweight installer and open the application to immediately access Writer, Spreadsheets, and Presentation modules.
- 3. Open your files: Directly open your existing .docx, .xlsx, or .pptx files and continue your work without worrying about format conversion issues.
Frequently Asked Questions
Why does a hybrid Exchange migration get stuck at 95% or Completing?
This typically occurs during the final synchronization phase where the system performs a final incremental sync, updates Active Directory attributes, and verifies folder hierarchy. Delays here are often caused by approval requirements, high resource utilization, or large item counts.
How long should a 50GB mailbox take to migrate?
While the initial synchronization depends heavily on your network bandwidth and Office 365 throttling, a 50GB mailbox can take several hours to a few days. However, the final 'Completing' state itself should normally finish within a few hours.
Does a stalled migration prevent the user from sending or receiving emails?
No, during the majority of the migration process, the user remains connected to their on-premises mailbox. Mailbox access is only briefly interrupted during the final cutover phase once the 'Completing' status successfully finishes.
What is the difference between a full and minimal hybrid configuration in migrations?
A full hybrid configuration supports features like cross-premises free/busy sharing and seamless mailbox moves, whereas a minimal hybrid configuration provides a faster initial setup but is generally intended for short-term migrations without long-term cross-premises collaboration features.
