I was configuring our production Nexus 7000 today and was also moving some modules around in order to accommodate better cabling options. The one problem that I had with our Nexus switches initially was insufficient 110 power leads in our lab to power them fully. Today I was able to resolve that by acquiring C19 pigtail cables to power al the power supplies on just 8 outlets (needed 12 to run all the power supplies).
What I have also done was move a few modules around in the chassis that where originally powered-down in order to run the chassis. What I noticed on the Nexus 7000 now is that you are able to poweroff a module even though a module in not installed:
N7K2# sh run | inc power
poweroff module 1
power redundancy-mode combined force
N7K2# sh module 1
As you can see there is no card installed in Module 1 but yet the power is disabled to that module.
I am trying to figure out if it is a safer option to keep the module powered-off for security and sanity or is it better to leave power to that slot.
For now, I am going to leave the power-off to that slot in order to
1) Prevent anyone from adding a module in the future
2) Also prevent a sudden power draw that could have a negative impact in the future (exceed power requirements)
3) Keep people honest – ensure a change will be submitted if more capacity is ever needed