SIRIS, ALTO, and NAS: Critical Backup Failure: Error Reading from Source File '/Home/Agents/#-TestDataset/Vddk-Fuse/VMDKname.Vmdk'



When attempting to backup a virtual machine under the agentless backup solution, you receive the error Critical backup failure: Error reading from source file '/home/agents/#-TestDataset/vddk-fuse/VMDKname.vmdk'. Expected bytes (value), actual bytes 0.


  • Datto SIRIS
  • Agentless Backups (VMWare)


  • Snapshots on the hypervisor require consolidation.
  • Changed Block Tracking (CBT) requires resetting.
  • The Datto appliance is full.
  • The live dataset on the Datto appliance is corrupt or unusable.


Attempt a backup after following each step:

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