Backing up to WD My Cloud says “sparsebundle is already in use”

21 Sep 2014

You own a WD My Cloud which you use to hold Time Machine backups of your Mac. Recently, however, backups fail because “The backup disk image XXX.sparsebundle is already in use”.

You need to reboot your WD My Cloud.

  1. Access WD MyCloud through the Web Interface. Mine is accessible at, but yours might be at a different location.

    You can also try on Safari: Preferences → Advanced → Include Bonjour in the Favourites Bar. You should then be able to find Bonjour → WDMyCloud on your favourites bar.

  2. On the WD My Cloud Web Interface you should then:
    • Settings → General → Mac Backups → toggle Time Machine off
    • Settings → Utilities → Device Maintenance → Reboot
    • wait for your device to reboot …
    • Settings → General → Mac Backups → toggle Time Machine on
  3. Open Time Machine preferences, select the appropriate disk, and try to backup again.

On my system Time Machine usually takes a while to “prepare the backup” before it actually starts backing up again.

Source: [1]