SysinfoException… a cryptic Vmware ESX 3.5 Vmotion error translated

Corner Edge has just completed a MAJOR implementation of a Vmware ESX cluster. We have greatly improved our data center capabilities and offerings.

This time around I want to add another tidbit to the online body of knowledge.

I recently received the following error while configuring Vmotion on our Vmware ESX 3.5 server cluster:

Error during the configuration of the host: SysinfoException: Node (VSI_NODE_net_tcpip_plumb) ; Status(bad0005)= Already exists; Message= Unable to Set

Now what is THAT supposed to mean? Vmware has amazing technology, but that “amazing” thing hasn’t yet reached their error messages.

It turns out that if your iSCSI traffic is configured with a specific network (Example:, and you try to configure Vmotion ports within the same network space (Example:, the Virtual Center wizard fails with the error above.

“Best practices” dictate that iSCSI traffic and Vmotion traffic should be completely separate from each other. But even if they are physically separated, and you may want use the same network space… well, you can’t.

Solution: Make the network address space for iSCSI (Example: 10.0.10.x) and Vmotion (Example: 10.0.20.x) different.

Oh and a better error message could be:

Wow buddy, you may think you’re really smart using the same network for iSCSI and Vmotion, but might as well forget it. I refuse to work that way. Make them separate networks!