Error Codes Wiki

Mac Time Machine Backup Failed Error

Errordisk errors

Overview

Time Machine 'backup failed' error prevents automatic backups, commonly caused by disk issues, insufficient space, or corrupted backup database.

Key Details

  • Time Machine shows 'The backup disk could not be found' or 'backup failed'
  • Can occur with external USB drives, NAS, or Time Capsule
  • Network backups are more prone to corruption than direct-attached
  • Backup database (.backupdb) can become corrupted over time
  • APFS snapshots may conflict with Time Machine on older systems

Common Causes

  • Backup disk disconnected, full, or failing
  • Corrupted Time Machine backup database
  • Network interruption during NAS-based backup
  • Backup disk formatted as wrong filesystem (needs HFS+ or APFS)
  • macOS update changed Time Machine behavior

Steps

  1. 1Check backup disk connection and available space in Disk Utility
  2. 2Run First Aid on the backup disk in Disk Utility
  3. 3Remove and re-add the backup disk in Time Machine preferences
  4. 4Delete the .inProgress folder on the backup disk if it exists: sudo rm -rf '/Volumes/BackupDisk/.inProgress'
  5. 5If corrupted beyond repair, erase the backup disk and start fresh backups

Tags

mactime-machinebackupdiskdata-protection

More in Disk Errors

Frequently Asked Questions

If you erase the backup disk, yes. Consider copying critical backups elsewhere first.