Azure File Sync - Repeated Transient Errors

Question

After updating to version 18.0 of the Azure File Sync agent, we are seeing frequent transient errors preventing the local server from downloading the new file versions. We are not using any tiering. Use case:

An automated process generates files in Azure File Share. This process then successfully triggers the Azure File Share to update the changes. Most files successfully copy to the local file server (located in Azure) once those changes are detected. However, ever since 18.0, one to a handful of files do not update correctly on the server side and are listed as a transient error. The file names and number of files impacted can differ each day. If we delete the files on the server, they do successfully download again. And sometimes there are no errors. The files are read-only and not open on the server at the time new versions get loaded into the Azure File Share. The only commonality seems to be this started happening after the update to 18.0.

The error we are seeing in the logs is:
0x80c8031d The file has changed, but the change hasn't yet been detected by sync. Sync will recover after this change is detected.

Per the troubleshooting article for Azure file sync, no action is required. However, the files do not update even after several hours.

Any help or insight would be appreciated!

Answer 1

@Greg Melnyk Welcome to Microsoft Q&A Forum, Thank you for posting your query here!

It sounds like you are experiencing issues with the Azure File Sync agent after updating to version 18.0.
The Azure File Sync agent v18 release is no longer available due to the following security issue:

Unauthorized users might be able to delete files in locations they don’t have access. For more information about this vulnerability, see CVE-2024-35253.

This issue is fixed in the Azure File Sync agent v18.1 release.

Based on the error message, please refer to the troubleshooting article : https://learn.microsoft.com/en-us/troubleshoot/azure/azure-storage/files/file-sync/file-sync-troubleshoot-sync-errors?tabs=portal1%2Cazure-portal
Can you please un-install and re-install the Azure File Sync agent.
Download the newest Azure File Sync agent installer from the Microsoft Download Center. To upgrade an existing Azure File Sync agent installation, uninstall the older version and then install the latest version from the downloaded installer. The server registration, sync groups, and any other settings are maintained by the Azure File Sync installer.

Azure File Sync Agent v18
https://www.catalog.update.microsoft.com/Search.aspx?q=5023058
Azure File Sync Agent v18.1

Additional information:

Check the sync interval: Make sure that the sync interval is set correctly. The sync interval determines how often the sync agent checks for changes in the Azure File Share. If the sync interval is too long, it may take longer for the changes to be detected. You can check the sync interval by using the Set-StorageSyncServiceConfiguration cmdlet.

Check the file size: Make sure that the file size is not too large. If the file size is too large, it may take longer for the changes to be detected. You can check the maximum file size supported by the sync agent by using the Get-StorageSyncServiceConfiguration cmdlet.

Check the network connectivity: Slow network connectivity can also affect the sync agent's ability to detect changes. Make sure that the network connectivity between the Azure File Share and the local file server is stable and fast.

Check the sync agent logs: Check the sync agent logs for any error messages related to the file that is not updating correctly. The error messages may provide clues as to what is causing the issue.

Try restarting the sync agent: Sometimes, restarting the sync agent can help resolve issues with file syncing. You can restart the sync agent by using the Restart-StorageSyncService cmdlet.

If you have tried all of these things and are still experiencing issues, I would like to work offline on this issue.

Please let us know if you have any further queries. I’m happy to assist you further.    

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Answer 2

Version 18.2 of the file sync agent resolved this issue.