Troubleshooting Sync: Drives, Tasks and Logs
Fix a drive that needs signing in again, a task that stopped or copied nothing, or a USB or S3 drive that won't connect, and check a run with Logs.
Start with the drive, then the task
Most problems in Sync come down to one of two things: a drive that has lost its connection, or a task that did exactly what it was set to do, just not what you expected. Check the drive first, because a task can't reach files on a drive that isn't connected.
A drive needs signing in again
Google Drive, Dropbox, OneDrive and Box stay connected through a login token, and that token can expire. If one of these drives has stopped working, reconnect it:
- Open the Drives tab.
- Open the three-dot menu next to the drive.
- Choose Authenticate and sign in to the account again.
Then choose Refresh from the same menu to reload the drive's file list.
Try Authenticate before Remove. Removing a drive doesn't delete the files inside it, it only breaks the connection to Sync, but you'd then have to add the drive again.
A task failed or stopped
- Check the error count. The task details and the task stats screen both show how many errors the run had.
- Read the errors. Choose ⋮ → Logs to see them.
- Check the drive. Open it in the Drives tab and confirm you can browse its files. If you can't, Authenticate it (above), reconnect the USB drive, or check your Amazon S3 details (below).
- Run the task again. Open it from the Tasks list and press ▶, or use ⋮ → Run to choose an operation. Selecting an operation starts the run straight away, so connect the drive first.
A stopped run doesn't resume. When you run the task again, it starts again from the beginning.
Reading Logs
Open the task, then choose ⋮ → Logs. Logs shows both transfers and errors. The task stats screen also shows what was transferred and any errors.
A task finished but nothing was copied
This usually isn't a fault. Sync scans both sides before it transfers anything, and if there are no files to process, the task simply completes with no stats screens. Check these before trying again:
- You ran Backup Sync or Restore Sync. They transfer only what has changed, so a second run straight after the first has nothing to do.
- The source is the folder you meant. A task can hold several sources. Use ⋮ → Add Source to include another folder.
- You ran the right operation. The ▶ button always uses the mode the task was created with, even if you chose a different operation from ⋮ → Run last time.
A task didn't run on its own
Sync doesn't run tasks automatically or in the background. Each run is started by you, so a saved task won't update anything until you open it and run it. See How to Create a Sync Task.
A task won't save
A task needs at least one source and a destination drive. Opening a folder picker doesn't select anything by itself: if you back out of it, the step still counts as empty. Open the picker again, choose a folder, and confirm the selection.
Files disappeared after a run
Only Full Sync deletes. It mirrors deletions, so a file deleted on one side is removed from the other. Backup, Backup Sync, Restore and Restore Sync never delete anything.
To stop a task deleting anything, use one of the four one-way operations instead. The differences are explained in Choosing the Right Task Operation.
A USB drive doesn't appear
Sync can only see a USB drive once your device has mounted it. On a phone, the usual causes are a cable that only carries power, or a phone that doesn't support USB OTG. USB Drive Setup covers each platform.
Amazon S3 won't connect
S3 doesn't use a sign-in, so Authenticate doesn't apply to it. It needs four values from the AWS console: bucket name, bucket region, access key ID and secret access key. Check that all four match what's in AWS, and that the access key is still active there. Setting Up Amazon S3 shows where to find each one.
Still stuck?
Contact us and include your device, the task's source and destination, the operation you ran, and any errors Logs shows for that run.
Related guides
- What is a Drive?: adding and managing drives, including the three-dot menu.
- How to Create a Sync Task: setting up a task and running it again.
- Choosing the Right Task Operation: what each of the five operations does.
FAQ
How do I reconnect a drive in Sync?
For Google Drive, Dropbox, OneDrive or Box, open the Drives tab, open the three-dot menu next to the drive and choose Authenticate, then sign in again. Amazon S3 has no sign-in, so check your AWS details instead.
Does removing a drive delete my files?
No. Remove only breaks the connection between the drive and Sync. The files stay where they are.
Why did my task finish without copying anything?
If there are no files to process, the task completes with nothing to show. That's normal for Backup Sync or Restore Sync when nothing has changed since the last run.
Where can I see what a task did?
The task stats screen and ⋮ → Logs both show what was transferred and any errors.
Does a stopped task pick up where it left off?
No. It starts again from the beginning the next time you run it.
Why didn't my task run overnight?
Sync doesn't run tasks automatically or on a schedule. You start each run yourself from the saved task.
Can a failed task delete my files?
Only Full Sync ever deletes files. Backup, Backup Sync, Restore and Restore Sync never delete anything.