Passthrough devices provide the means to more efficiently use resources and improve performance in your environment. You can configure a passthrough PCI device on a virtual machine in the vSphere Web Client.

When using passthrough devices with a Linux kernel version 2.6.20 or earlier, avoid MSI and MSI-X modes because these modes have significant performance impact.

Verify that a passthrough networking device is configured on the host of the virtual machine. See Enable Passthrough for a Network Device on a Host.

1

Locate the virtual machine in the vSphere Web Client.

a

Select a data center, folder, cluster, resource pool, or host and click the Related Objects tab.

b

Click Virtual Machines and select the virtual machine from the list.

2

Power off the virtual machine.

3

On the Manage tab of the virtual machine, select Settings > VM Hardware.

4

Click Edit and click the Virtual Hardware tab.

5

Expand the Memory section, and set the Limit to Unlimited.

6

From the New device drop-down menu select PCI Device and click Add.

7

From the New PCI device drop-down menu select the passthrough device to use, and click OK.

8

Power on the virtual machine.

Adding a DirectPath I/O device to a virtual machine sets memory reservation to the memory size of the virtual machine.