VMware Restores Using NBD Are Slow When Windows Proxy Has Autotuning Enabled

When you restore a VMware VM with NBD transport mode using a VSA proxy that runs on Windows, the restore might be slow if the Windows proxy machine has autotuning enabled.

Symptoms

A restore of a VMware virtual machine that uses NBD transport mode might be slow when a Windows proxy is used. You can run the testvminfo utility to compare average speeds in the TestVMInfo.log file with the average speeds in the vsrst.log file.

Causes

This issue can occur when a VSA proxy runs on a Windows machine that has autotuning enabled.

Resolution

To resolve this issue, perform the following steps:

1. Run the following command on the Windows proxy machine: netsh int tcp set global autotuninglevel=disabled
2. Resubmit the restore job.