Windows 10 and OneDrive Files On-Demand
OneDrive files On-Demand is a new feature introduced by Microsoft in Windows 10 Fall Creators update. With ‘Files On-Demand’, you can access all your files stored in OneDrive cloud (using the File Explorer) without having to download all of them and use storage space on your device. This feature is similar to OneDrive placeholder files in Windows 8.1.
Once ‘Files On-Demand’ feature is activated, all your OneDrive files are accessible either locally (where files are downloaded and available locally on your device) or cloud-only (where files are stored on the cloud and are available only when downloaded to the device) through the File Explorer.
So, if you have a profile in SyncBack that backup all files on your local OneDrive folder (both locally and cloud-only files), then the profile run may fail with errors when copying cloud-only files (because they are not available on your local device). If you wish, you can configure the profile to ignore cloud-only files from your backup selections, which you can configure under:
Modify > Expert > Compare Options > Attributes > enable ‘Do not copy offline files’ option
(Note: The 'offline file' in this NTFS file attribute option means a file isn't stored locally, i.e. it's not stored on a connected drive. So if a file is stored only on the cloud then it is considered, by Windows, to be offline. Yes, it is confusing.)
Alternatively, you can create OneDrive cloud profile to upload/download files to/from OneDrive cloud to destination using SyncBackPro. Refer to this article on how to create a cloud profile. (Note - While the article references Google Drive, this guide can also be used with other cloud services, e.g. Microsoft OneDrive, Dropbox, etc.)