Symptoms
Entire Mac backup or Disks backup fails with the following error in log:
error 0xfff1: Resource deadlock avoided
Path mentioned in error log is similar to:
path: /System/Volumes/Data/Users/<username>/Library/CloudStorage/...
Cause
The folder /Users/[username]/Library/CloudStorage/<XXXXXX> is the folder for iCloud files on Mac. These files are stored on the cloud rather than on the local machine.
Solution
Add CloudStorage folder to exclusions:
- Select your backup task in the list and click Settings
- In settings window, go to Exclusions
- Click on "+" button, then select Exclude specific file or folder. Browse to the folder /Users/<username>/Library/CloudStorage/<....> that is mentioned in the error log, select it and click Exclude to add this folder to the list of exclusions.
- Click OK to save changes.