If a vSphere distributed switch is removed from vCenter Server in an unsupported way, for example, hosts being forcibly removed from the distributed switch, or the vCenter Server database being reconstructed due to corruption, you might encounter an invalid device backing error for the network interface of a virtual machine (vNIC).

Virtual machines or vNIC devices are pointing to a distributed switch or distributed port group that no longer exists. You might also not be able to remove the corresponding proxy switches on the hosts because the ports from the incorrectly removed distributed switch are still in use.

To resolve this issue, you must migrate all affected hosts and virtual machine NIC devices to a separate network. You can apply a valid configuration after the migration.

To migrate the affected virtual machines and their vNIC devices to a separate network, use the Migrate virtual machine networking wizard in the vSphere Client and vSphere Web Client, as described in the vSphere Networking Guide. Select all virtual machines listed with no networking – these are the virtual machines with the invalid device backing error. After the vNIC devices are migrated away from the invalid distributed switch, you can remove the proxy switch, or allow vCenter Server to do it automatically. vCenter Server automatically removes a proxy switch from a host when it detects a proxy switch without a corresponding distributed switch.

1. In the vSphere Client, navigate to the host.
2. Click the Configuration tab.
3. Click Networking, and select the vSphere Distributed Switch view.
4. Migrate one or more NICs from the old switch to the new one:
   1. In the section of the new distributed switch, click Manage physical adapters.
   2. Add a NIC belonging to the removed switch to an uplink.
   3. Click OK.
5. Migrate the VMkernel adapters for management traffic to the new switch:
   1. In the section of the new distributed switch, click Manage Virtual Adapters.
   2. In the Management Virtual Adapters wizard, click Add and select Migrate existing virtual adapters.
   3. Select the affected VMkernel adapters for management traffic from the old switch and assign them to a port group from the new distributed switch.
   4. Click Next and Finish.
6. Migrate the virtual machine network adapters on the host from the old switch to the new one by assigning them separately to port groups of the new switch, or by using Migrate Virtual Machine Networking wizard on the parent datacenter in the Networking inventory view.

   Select all virtual machines with no networking connectivity.

In the vSphere Client, after you move the host to the new switch with a valid uplink to carry traffic, the error disappears as soon as you switch virtual machine traffic to a port group that has uplink connectivity.

Migrate networking from the removed distributed switch to a new one with the vSphere Web Client

In vSphere 5.1 and later, to migrate the physical NICs, VMkernel adapters and virtual machines from an affected host to a separate network, for example on a new distributed switch, perform these steps in the vSphere Web Client:

1. In the vSphere Web Client, navigate to the host.
2. Select the Manage tab.
3. Select the Networking tab and click Virtual switches.
4. Migrate one or more NICs and VMkernel adapters from the old switch to the new one:
   1. Select the new distributed switch and click Migrate physical or virtual network adapters to this switch.
   2. In the Manage physical network adapters page, assign one or more NICs to uplinks of the new switch, and click Next.
   3. In the Manage virtual network adapters page, migrate the VMkernel adapters for management traffic from the old switch by assigning them to a port group from the new switch, and click Next.
   4. Click Next and Finish.
5. Migrate the virtual machine network adapters on the host from the old switch to the new one by assigning them separately to port groups of the new switch, or by using Migrate VM to Another Networking option on the parent datacenter.

   Select all virtual machines with no networking connectivity.

In the vSphere Web Client, after you move the host to the new switch with a valid uplink to carry traffic, the error disappears as soon as you switch virtual machine traffic to a port group that has uplink connectivity.

Additional Information

• 日本語: 仮想マシン NIC 上の「無効なバッキング」エラー (2068542)