This article applies to the following sync applications:
WebStorage Sync for Windows
WebStorage Sync for Mac
When using WebStorage Sync, we recommend keeping your sync folder on your computer's internal drive — not on an external HDD, SSD, USB flash drive, or memory card.
External drives can add extra storage, but their connection isn't as stable as an internal drive. If the drive disconnects, sync can behave unexpectedly.
What can go wrong
The external drive disconnects unexpectedly
A loose USB connector, a faulty cable, insufficient power, sleep mode, or an improper eject can all cause an external drive to go offline temporarily. When this happens, WebStorage Sync may not be able to find your sync folder, which can lead to:
Sync pausing or failing
Interrupted uploads or downloads
Duplicate files or conflicted copies
Files being mistaken as deleted — and that deletion syncing to your other devices
The drive path changes
After reconnecting an external drive, its drive letter (Windows) or mount path (macOS) can change. If WebStorage Sync can't find the original location, it may ask you to set up the sync folder again — or even re-download all your files.
Performance and compatibility issues
WebStorage Sync continuously scans and compares files. An external drive's speed depends on the USB interface, cable, hub, and file system in use, which can slow down sync or cause file status to be read incorrectly.
Recommended setup
Set your sync folder on your computer's internal drive.
Running low on space? Adjust which folders are included in sync, rather than moving your sync folder to an external drive.
Use an external drive for extra backups, not as your primary sync location.
If you need to change your sync path, wait for sync to finish and back up your important files first, then follow the in-app instructions.
Reminder: Sync is not the same as backup.
Sync applies every change and deletion across all your devices. Backup keeps an independent copy. For important files, we recommend keeping both a synced copy and a separate backup.
Already syncing from an external drive and running into errors?
If your sync folder is set on an external drive and you're seeing sync failures, files that won't upload, or a "can't find the sync folder" error, pause or quit WebStorage Sync first to stop the issue from continuing to sync.
Your local files are still there, but haven't uploaded to the cloud
Move or copy any files that haven't uploaded yet to a safe location outside the sync folder.
Change your Sync path back to your computer's internal drive — for example, the C: drive on Windows, or a folder on your Mac's internal drive.
Launch WebStorage Sync and let it finish syncing your cloud data with the new local sync folder.
Confirm sync has completed, and check that both your cloud and local files look correct.
Move the files you set aside earlier back into the new sync folder and let them upload to the cloud.
Double-check that everything has finished syncing.
Note: Don't delete the original files on the external drive until you've confirmed everything is safely synced and backed up. If you notice a large number of deleted files, conflicted copies, or you're not sure what state your data is in, stop syncing and contact WebStorage support for help.
More
Limited space on your C: drive, consider switching to xDrive instead — it can significantly reduce the local storage space you need. View Get Started with xDrive for more information.
Or you can fill out the [Problem Report] and our customer support will further assist you.