Query on sync

Question

Hi All,

We are using Microsoft 365 with E5 licenses. I have a SharePoint Online site that holds almost 2 TB of data. Recently, one user’s local folder was synced to this SharePoint site (via the OneDrive sync client, I believe), and it appears that their local content overwrote a large portion of the existing data on the site. The site owner noticed this only after about a month, and at this point there seems to be no way to recover the overwritten data. The owner was able to identify the user who mapped/synced it.

The site owner would like to know if there is any way to identify whether any other users have synced/mapped this SharePoint document library to their local machines in a similar way. Please guide me.

Answer 1

Hi Rising Flight

Welcome to Microsoft Q&A forum 

I am sorry to hear that you are experiencing the issue with SharePoint syncing. To find out who is syncing the affected library, you can check via Microsoft 365 Admin Center 

-Go to https://admin.microsoft.com  

-Settings > Org settings > Services tab > scroll down and click Reports 

-Uncheck the box “Display concealed user, group, and site names in all reports” 

-Click Save 

-Navigate to Reports > Usage > SharePoint > Activity tab  

-Choose 90 days or 180 days (top-right corner) 

-Click Export > open the downloaded CSV in Excel 

-In Excel file, find people who are currently syncing the library to their computers 

 

Recommend for future risk prevention 

Disable sync completely for this sensitive library 

Open SharePoints site > Library Settings > Advanced Settings > Offline and sync > set to No 

Tenant-wide sync restriction by Powershell 

Set-SPOTenantSyncClientRestriction -Enable $true -GrooveBlockOption "OptOut" 

(reference: Set-SPOTenantSyncClientRestriction (Microsoft.Online.SharePoint.PowerShell) | Microsoft )

---

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".   

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Answer 2

To identify whether other users have synced or mapped the SharePoint document library to their local machines, you can utilize the SharePoint site usage reports available in the Microsoft 365 admin center. These reports provide insights into user activity, including who has accessed the site and potentially synced content.

Additionally, you can review the SharePoint dataset from Microsoft Graph Data Connect, which can help analyze site lifecycle, ownership, and storage used by SharePoint sites and OneDrive accounts. This dataset can provide information on which users have interacted with the library and how much storage they are utilizing.

It's important to note that while these tools can help you gather insights, they may not provide a direct list of users who have synced the library specifically. However, they can give you a broader view of user interactions with the site, which may help in identifying potential issues related to syncing.

For future prevention, consider implementing policies or training for users regarding the impact of syncing local folders to SharePoint libraries, especially when dealing with large amounts of data.

---

References:

• SharePoint storage planning
• SharePoint and OneDrive data resiliency in Microsoft 365