Hyper-V Restore Job Fails, Cannot Connect to Utility on Host

Hyper-V VM restore job fails and an error message appears.

Symptom

When restoring a Hyper-V VM, restore job fails and the following error appears in activity log:

Failed to connect to the Hyper-V restore utility on host xxxxx

In the restore job debug log, the following error messages appear:

Failed to connect to xxxxx:10218. error:Attempt to connect timed out without establishing a connection (rc=-536805332)

Failed to connect to xxxxx:10218, error -536805332

Solution

Normally, such problem is caused as the connection between backup proxy and Hyper-V host is blocked by firewall. If possible, turn off the firewall and try restore again. If you cannot turn off the firewall, register the port (or port range) used by restore job to the firewall exception.

By default, the restore job randomly chooses an available port in the range of 1024 and 65535. You can manually specify the range by registry values set in Hyper-V host.

Follow these steps:

1. Log into Hyper-V host.
2. Run the command regedit to open registry editor.
3. Navigate to the following registry key (create keys if any of them does not exist):

HKEY_LOCAL_MACHINE\SOFTWARE\Arcserve\Unified Data Protection\Engine\HyperVRestoreStub

4. Create the following two registry values (DWORD):

PortMin

PortMax

5. Specify values with beginning and end number of the port range.

Notes:

• Mandatory Range of specified values: 1024-65535
• You can specify the same number for both registry values. In this case, the fixed port number is used for the restore job. When multiple restore jobs run simultaneously and as soon as one restore job occupies this port, then other restore jobs fail.