6.0.1

Unable to Add a Physical Adapter to a vSphere Distributed Switch
That Has Network I/O Control Enabled
You might be unable to add a physical adapter with low speed, for example, 1 Gbps, to a vSphere
Distributed Switch that has vSphere Network I/O Control version 3 configured.
Problem
You try to add a physical adapter with low speed, for example, 1 Gbps, to a vSphere Distributed Switch that
is connected to physical adapters with high speed, for example, 10 Gbps. Network I/O Control version 3 is
enabled on the switch and bandwidth reservations exist for one or more system traffic types, such as
vSphere management traffic, vSphere vMotion traffic, vSphere NFS traffic, and so on. The task for adding
the physical adapter fails with a status message that a parameter is incorrect.
A specified parameter was not correct: spec.host[].backing.pnicSpec[]
Cause
Network I/O Control aligns the bandwidth that is available for reservation to the 10-Gbps speed of the
individual physical adapters that are already connected to the distributed switch. After you reserve a part of
this bandwidth, adding a physical adapter whose speed is less than 10 Gbps might not meet the potential
needs of a system traffic type.
For information about Network I/O Control version 3, see the vSphere Networking documentation.
Solution
1 In the vSphere Web Client, navigate to the host.
2 On the Manage tab, click Settings.
3 Expand the System group of settings and click Advanced System Settings.
4 List the physical adapters that you want to use outside the scope of Network I/O Control as a comma-
separated list to the Net.IOControlPnicOptOut parameter.
For example: vmnic2,vmnic3
5 Click OK to apply the changes.
6 In the vSphere Web Client, add the physical adapter to the distributed switch.
Troubleshooting SR-IOV Enabled Workloads
Under certain conditions, you might experience connectivity or power-on problems with virtual machines
that use SR-IOV to send data to physical network adapters.
Virtual Machine That Uses an SR-IOV Virtual Function Fails to Power On
Because the Host Is Out of Interrupt Vectors
On an ESXi host, one or more virtual machines that use SR-IOV virtual functions (VFs) for networking are
powered off.
Problem
On an ESXi host, one or more virtual machines that use SR-IOV virtual functions (VFs) for networking fail to
power on if the total number of assigned virtual functions is close to the maximum number of VFs specified
in the vSphere Configuration Maximums guide.
Chapter 8 Troubleshooting Networking
VMware, Inc. 87