1220 - ESE: Files are skipped during backup with error "Cloud files are not supported"

Symptom

Certain files are skipped during a backup, with the logs showing the error "Cloud files are not supported". This can happen whether or not a cloud service such as OneDrive is running on the machine/server. This error can appear even when the appropriate permissions are set and files are syncing correctly. 

Cause

Because we cannot backup files for which the data is not present locally, ESE attempts to detect stubbed OneDrive files on a machine/server by checking for the following factors:

• file size > 0
• size on disk = 0
• reparse point = true
• RecallOnDataAccess attribute = true

If any one of these is true for a file, the file will be seen as a cloud file by ESE and will be skipped during backup.

Even if OneDrive is not running on the machine/server, the files may have been moved from OneDrive to their current location, retaining some of their attributes and resulting in the same error. In fact, the issue is not unique to OneDrive and any other cloud service could have these attributes set explicitly or inherited.

Solution

There are three possible solutions to this error:

Solution 1: Change settings in OneDrive

If OneDrive is running on the machine/server, try the following steps:

1. Right-click the relevant OneDrive file/directory in your file explorer and check Always keep on this device.

2. Check the Files On-Demand setting in OneDrive. This setting must be disabled for backups to work. 

Note: After disabling this option, the OneDrive files will need to be rehydrated, which will take time. If a backup is attempted before rehydration is complete, you may still get errors. 

Solution 2: Apply exclusions

Exclude any directories on which you are using third-party archiving or data tiering. Article 1085 may be useful if these directories are being included by VSS.

Solution 3: Disable VSS

If OneDrive is not running on the machine/server, you can consider disabling VSS (if this is an option for you) before attempting the backup again. However, this measure should only be used as a last resort as it may have a number of knock-on effects.

To disable VSS, go to Options > Advanced in your ESE agent.