When you migrate files from an on-premises file server to OneDrive during a weekend cutover, users often report that shared links created before the migration no longer work. This happens because the file paths change when data moves from a network share to a cloud tenant. The original sharing links point to the old server location, and OneDrive cannot resolve those references after the cutover. This article explains the technical reason for broken recent links and provides a step-by-step admin checklist to preserve link integrity during the migration.
Key Takeaways: Preserve Sharing Links During File Server Migration
- SharePoint Migration Tool (SPMT) > Preserve sharing links: When you check this setting, SPMT rewrites link references to the new OneDrive location during migration.
- File path change detection: OneDrive uses a unique file ID for each item. If you move the file without preserving the ID, all existing links break.
- Migration Assessment Scan: Run this scan before cutover to identify all shared files and their link count, so you can plan the migration timing and method.
Why File Server Migration Breaks Recent OneDrive Links
When users share a file from a file server, the sharing link contains the server path, such as \\fileserver\shared\project\report.xlsx. OneDrive for Business stores a mapping between that server path and the file’s unique ID in the SharePoint content database. After migration, the file exists in a new OneDrive site with a new file ID. The old server path no longer resolves to any valid file in the tenant.
Microsoft 365 sharing links are tied to the file’s internal ID, not its display name or folder path. When you copy or move a file to OneDrive using Windows File Explorer or a drag-and-drop method, the file receives a new ID. All previous sharing links become orphaned. Only migration tools that preserve the file ID, such as the SharePoint Migration Tool with the correct option enabled, can keep existing links functional.
The term “recent links” refers to the list of recently accessed files that appears in the OneDrive web interface and Microsoft 365 apps. These links also rely on the file ID. After migration, the recent links list shows broken entries because the old IDs no longer exist in the user’s OneDrive.
Admin Checklist: Preserve Links During Weekend Cutover
- Run the Migration Assessment Scan
Open the SharePoint Admin Center. Go to Migration > Assessment. Run a full scan on the file server share. The report lists every shared file, the number of sharing links, and the last access date. Use this data to decide which files must keep their links and which can be recreated. - Enable the Preserve sharing links option in SPMT
Download and install the SharePoint Migration Tool version 3.12 or later. When you create a new migration task, expand the Advanced settings section. Check the box labeled Preserve sharing links during migration. This setting tells SPMT to copy the file ID from the source to the destination. - Use SPMT bulk migration instead of manual copy
Do not use Windows File Explorer copy, robocopy, or any third-party tool that does not preserve SharePoint file IDs. Configure SPMT to point to the source file server path and the target OneDrive URL. SPMT handles the ID mapping automatically when the preserve option is active. - Perform a pilot migration on a small folder
Select one folder with no more than 50 files. Run the migration with the preserve option enabled. After completion, ask the folder owner to test a few shared links from before the migration. If the links open correctly, proceed with the full cutover. - Schedule the cutover during a low-activity window
Weekend cutovers are standard, but confirm that no users have pending sharing link creation during the migration window. Send a notification 48 hours before cutover asking users to avoid sharing files from the server during the migration. - Verify link integrity after migration
Run the SPMT post-migration report. Look for any files that show a status of Link preservation failed. For those files, manually reshare them from the new OneDrive location. Use the OneDrive Sharing report in the Microsoft 365 admin center to view all active sharing links for each user site. - Redirect the old file server path to OneDrive
After migration, configure a DFS link or a simple URL redirect on the file server. When a user clicks a file shortcut that points to the old server path, the redirect opens the OneDrive web URL for that file. This reduces user confusion and support tickets.
Common Issues After File Server Migration and How to Fix Them
Users report broken links in the OneDrive Recent list
If the recent list shows files with a red X or a “File not found” error, the migration did not preserve the file IDs. To fix this, use SPMT to re-migrate only those specific files with the preserve option enabled. If the files are already in OneDrive, delete them first, then re-run the migration. After re-migration, ask the user to refresh the OneDrive web page by pressing F5.
Shared links from external users stop working
External sharing links that were created before migration also break because the file ID changed. The preserve option in SPMT does not retroactively fix links that were already sent. You must generate new sharing links for external users. Use the Microsoft 365 admin center to view all external sharing links per site, then notify external users with the new link.
Migration tool shows “Link preservation not supported for this file type”
SPMT cannot preserve links for files larger than 15 GB or for files stored in certain encrypted folders. Check the SPMT error log for the exact file name. For these files, inform the file owner that they must reshare the file manually after migration. Move these files in a separate batch to avoid blocking the entire migration.
File Server Migration Methods: Link Preservation Comparison
| Item | SharePoint Migration Tool (SPMT) | Windows File Explorer Copy |
|---|---|---|
| Preserves file ID | Yes, when the preserve option is enabled | No |
| Preserves sharing links | Yes | No |
| Supports bulk migration | Yes, up to 100 TB per task | No, manual per folder |
| Handles file version history | Yes, up to 50 versions | No |
| Requires admin credentials | Yes, SharePoint admin role | No |
| Post-migration link report | Yes, included in the SPMT summary | No |
The table above shows that only SPMT with the preserve option offers link preservation at scale. Any manual copy method will break all existing sharing links.
You now have a clear checklist to prevent broken sharing links during a weekend file server migration to OneDrive. Run the assessment scan first, enable the preserve links option in SPMT, and verify link integrity after cutover. For files where link preservation fails, use the OneDrive Sharing report in the Microsoft 365 admin center to identify and reshare them. As an advanced tip, create a PowerShell script that exports all sharing links from the old file server using the Get-SPOSite and Get-SPOSiteSharingLink cmdlets before migration, then compare against the post-migration report to catch any missed links.