Critical Backup Failure: Error Reading from Source File '/Home/Agents/#-TestDataset/Vddk-Fuse/VMDKname.Vmdk'
Issue
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.
Environment
- Datto SIRIS
- Agentless Backups (VMWare)
Cause
- 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.
Resolution
Attempt a backup after following each step:
- Consolidate snapshots on the hypervisor (external link).
- Ensure that the Datto appliance has adequate free space for a snapshot.
- On the Datto appliance, delete the live dataset for the virtual machine.
- Verify that you can successfully take a manual quiescing snapshot, then Reset the Changed Block Tracking on VMWare (external link).