Upgrade FAS2020A to FAS2040A

Can you upgrade only the controller heads from a FAS2020 to a FAS2040?

Or do you need to purchase a full FAS2040 chassis and move the disks from the FAS2020 to the FAS2040?

Re: Upgrade FAS2020A to FAS2040A

Yes.  They use the same chassis, so it is a controller swap.  Work with your netapp team/var on a quote for new controllers and trade-in on the 2020 controller (if possible to trade-in) then you can have a short outage for the controller swap.