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OneDrive Sync Client an Important Part of Microsoft 365
The OneDrive sync client makes working with files and folders stored in SharePoint Online or OneDrive for Business easier by synchronizing changes to local copies. Users can then work on the local copies in the knowledge that the OneDrive sync client will make sure that their changes will be uploaded to the server-based master copy. The AutoSave feature in the Office applications takes advantage of the background synchronization to ensure that the chance of losing work in disrupted edit sessions is now very low. I think it’s fair to say that the OneDrive sync client is a real success story for Microsoft 365.
Several years ago, things weren’t quite so seamless, but Microsoft put in a lot of work to improve the functionality of the sync client. The introduction of differential sync in 2020 was a particularly important step, especially for working with large files.
OneDrive Synchronization of Deleted Files
When a user deletes a file from a SharePoint Online or OneDrive for Business document library, the file moves into the site Recycle Bin. If the OneDrive sync client synchronizes local copies of files from the site, the current behavior is that the OneDrive sync client will move the local copy of the file into the workstation’s recycle bin (or Trash on macOS). Figure 1 shows a set of files deleted from a synchronized document library after the OneDrive sync client moved the local copies to a PC’s recycle bin.
If the user restores the file from the site recycle bin, the local copy remains in the workstation recycle bin. This file can be deleted from the workstation recycle bin without affecting the server-based copy. In short, copies of files placed in the workstation recycle bin lose connection with the server-based file.
The Fix
Microsoft proposes to fix the problem (MC1269861, 3 April 2026) by updating the OneDrive sync client so that it no longer processes cloud-initiated file deletions by moving the local synchronized copy of the deleted files into the workstation recycle bin. Instead, the OneDrive sync client will simply remove the local copy from the local folder replica. The change means that the only copy of the deleted file will be in the site recycle bin. Microsoft says that this change will “improve OneDrive sync performance and make file recovery more predictable.” In other words, there will only be a single authoritative copy of deleted files and folders to manage if someone needs to recover an item.
Files that use the on-demand feature are unaffected by the change because the OneDrive sync client doesn’t process these files. Instead, if a user wishes to work with an on-demand file, the application must pause to download the content from the server. Another point is that if a user deletes a local copy of a synchronized file, the operating system will move the file to the local recycle bin and the OneDrive sync client will move the server-based copy to the site recycle bin.
The new behavior will reach general availability for all Microsoft 365 tenants through the deployment of an updated OneDrive sync client starting in early May 2026 that’s due for completion by late May 2026. Administrators can’t do anything to influence or block the change. It will just happen.
Performance Improvements
Microsoft also asserts that the change will improve the performance for synchronization, especially for users who work with large document libraries. They don’t give any more details about why this should be so, but I guess that if you have more files in a library, there’s more likely to be deletions going on and not having to worry about creating local copies will make the work of the OneDrive sync client easier.
Removing complexity and the potential for confusion from file synchronization operations makes sense. It’s an example of software tweaking based on hard experience that I doubt many will notice.
So much change, all the time. It’s a challenge to stay abreast of all the updates Microsoft makes across the Microsoft 365 ecosystem. Subscribe to the Office 365 for IT Pros eBook to receive insights updated monthly into what happens within Microsoft 365, why it happens, and what new features and capabilities mean for your tenant.