6.0.1

Table Of Contents
Troubleshooting USB Passthrough Devices
Information about feature behavior can help you troubleshoot or avoid potential problems when USB
devices are connected to a virtual machine.
Error Message When You Try to Migrate Virtual Machine with USB Devices
Attached
Migration with vMotion cannot proceed and issues a confusing error message when you connect multiple
USB devices from an ESXi host to a virtual machine and one or more devices are not enabled for vMotion.
Problem
The Migrate Virtual Machine wizard runs a compatibility check before a migration operation begins. If
unsupported USB devices are detected, the compatibility check fails and an error message similar to the
following appears: Currently connected device 'USB 1' uses backing 'path:1/7/1', which is not
accessible.
Cause
To successfully pass vMotion compatibility checks, you must enable all USB devices that are connected to
the virtual machine from a host for vMotion. If one or more devices are not enabled for vMotion, migration
will fail.
Solution
1 Make sure that the devices are not in the process of transferring data before removing them.
2 Re-add and enable vMotion for each affected USB device.
USB Passthrough Device Is Nonresponsive
USB devices can become nonresponsive for several reasons, including unsafely interrupting a data transfer
or if a guest operating system driver sends an unsupported command to the device.
Problem
The USB device is nonresponsive.
Cause
A data transfer was interrupted or nonsupported devices are being used. For example, if a guest driver
sends a SCSI REPORT LUNS command to unsupported USB flash drives, the device stops responding to all
commands.
Solution
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Physically detach the USB device from the ESXi host and reattach it.
If the host is not physically accessible, you can shut down the host (not reboot) and leave it turned off
for at least 30 seconds to ensure that the host USB bus is completely powered off.
When you turn on the host, the USB device is restored from its nonresponsive state.
vSphere Troubleshooting
18 VMware, Inc.