This is a fun ad-hoc solution to a simple controls problem I had.

I have an error term for a controller where the sample period has to be large, and the measurements are noisy. But I also have a a really high tolerance for error around the setpoint, and the purpose of the controller is to provide more consistent control and noise behavior within some constraints. As long as the temperature stays close to the setpoint and does not wander too far, I don't care how noisy the process is so long as the controller's behavior is flat. So I have an opportunity to replace the normal error measurement with something else.

This is a note about an annoying scenario with a simple solution. 👍

Let's say you've resized a swap partition.

After recreating the newly-resized swap partition, your new partition probably has a new UUID.

This can cause problems, like preventing hibernate on laptops, if it is not taken care of properly. It can cause other problems with the system as well.

You have to update /etc/fstab with the UUID of the newly formatted swap partition in order for the system to recognize it.