I came across a strange issue recently when configuring a new vDS in vSphere 5. I had already configured two VMkernel adapters but for some reason one of them half created. Only one was visible when viewing the vDS settings on the host:
When attempting to create a new one I’d receive a message stating that one already existed (apologies I don’t have the screen shot as I fixed it before creating this post). I was unable to locate this within vCenter or even when connecting directly to the host. Only way I could resolve it was to enable and connect to the host via SSH and list all VMkernel adapters with the following command:
esxcli network ip interface list
Now I could see the offending adapter. Next option was to remove it:
esxcli network ip interface remove –i <Adapter name>
Now when listing the adapters again it was successfully remove and could be re-added again within vCenter.