Symptoms

You back up Hyper-V virtual machines using Agent for Hyper-V. Agentless backup fails with error:

Disk '<...>.vhdx' is not found.

Example of full error log: click to expand

| error 0x95000d: Failed to perform the requested operation. 
| line: 0xd1ab7fa1e56ec835 
| file: e:\215\enterprise\disk_manager\daapi1\virt_op.cpp:1277 
| function: DiskManagement::VirtualMachineOpenOpImpl::OpenVm 
| $module: disk_bundle_vsa64_10130 
| 
| error 0x728003: Failed to prepare for backup. 
| line: 0xf56319586dedc182 
| file: e:\215\enterprise\migration\impl\computer_browser.cpp:113 
| function: MigrationManagement::`anonymous-namespace'::SubscribingEmulatedComputer::OpenDisks 
| $module: disk_bundle_vsa64_10130 
| 
| error 0x53013b: Disk 'E:\Virtual Hard Disks\AcronisBackup.vhdx' is not found. 
| line: 0x3e00788fd9d77c02 
| file: e:\196\enterprise\virtualware\raw\microsoft\hyperv\server\hdd_control.cpp:564 
| function: VirtualWareRaw::`anonymous-namespace'::NativeCbtInfoFactory::GetCbtInfo 
| $module: hv_srv_vsa64_10130

 

Troubleshooting

1. Verify that virtual disk that is mentioned in the error message exists and was not renamed or moved. 
2. Verify that snapshot creation in Hyper-V works properly. Refer to Acronis Cyber Backup: Troubleshooting Hyper-V snapshot issues

If suggested steps did not resolve the issue and Hyper-V snapshots are created correctly, collect diagnostic information and contact Acronis Support with reference to this article.

Collect information

1) System information from the affected Agent for Hyper-V

• Acronis Cyber Backup 12.5: see this article for instructions
• Acronis Cyber Protect Cloud: see this article for instructions

2) Logs with information about VM checkpoints operations and failures related to Hyper-V VMs snapshots/checkpoint creation failure.

On Hyper-V server, open Windows Event Viewer (press Win+R to open the Run dialog, enter eventvwr.msc and hit OK). You need the following logs:

• Event Viewer > Applications and Services Logs > Microsoft > Windows > Hyper-V worker -> Admin
• Event Viewer > Applications and Services Logs > Microsoft > Windows > Hyper-V-VMMS > Admin + Operational

Right-click on the log and select Save all events as, and save the log as .evtx file