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.
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
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.
- In the vSphere Web Client, navigate to the host.
- On the Manage tab, click Settings.
- Expand the System group of settings and click Advanced System Settings.
- 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
- Click OK to apply the changes.
- In the vSphere Web Client, add the physical adapter to the distributed switch.