SIRIS, ALTO and NAS: File System unmounted / Volumes are unmounted error



This article discusses troubleshooting for the error: File System Unmounted or Volumes Are Unmounted.


  • Datto SIRIS
  • Datto ALTO
  • Datto NAS


This error can result from the following conditions:

  • A power outage occurred on-premises and the unit did not properly shut down.
  • The device was hard rebooted by a device operator or by a power failure.
  • The device's storage array was recently upgraded to a total capacity in excess of 5 TB.
  • An attempt to delete a backup volume is still in process, or the deletion of the volume did not complete fully.


Figure 1: Volumes are unmounted error message (click to enlarge)

  • If you see this error message as a result of a hard reboot, soft rebooting the appliance from its Device Settings page may resolve the issue.
  • If you just completed a device upgrade, the appliance's first initialization may take longer to complete. Allow 10 to 15 minutes for this to occur.
  • If you see this message after deleting a very large backup volume (1 TB or larger), the removal of the dataset may still be in progress. Allow the appliance 5 to 10 minutes to complete the operation. If the message persists, attempt to delete the volume again.

If you continue to see this message after performing relevant troubleshooting, contact Datto Technical Support for assistance.

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