Couldn’t you replace the magnetosphere with some sort of faraday cage-type setup? The other things aren’t necessarily deal breakers for various use-cases (e.g. off-site backups and other sorts of cold-storage situations where)

I'm being a bit hyperbolic, but Ceres is a ball of ice so large it's rounded by its own gravity [0]. I'm pretty sure you could engineer a shelter by using the waste heat of the nuclear reactor to bore a tunnel into the ice.

I wish I knew the math to calculate how much energy would be needed to send data to Ceres and back, because I think the transmission energy might be large enough that it would prevent the cold-storage use case. Reading and writing from flash storage probably requires less energy. That means this Ceres data center would be best suited towards low data, high computation, latency is irrelevant computation. Maybe brute forcing encryption keys or advanced fluid dynamics modeling.

[0] Ceres is 50% water by volume.

Perfect for cold storage then?

The entire benefit of Ceres is that you get access to nuclear power without having to risk radiation exposure for Earth. Cold storage is famously low power usage, the storage drives are powered off. It doesn't take advantage of the entire point of building a datacenter on Ceres. It takes orders of magnitude less energy to fill a SD card full of data on Earth and leave it here than it would to launch it into space in case we need to read from it in the future.

I was trying to be funny in my comment. But thanks for a very informative reply!

I mean with a fission reactor right there now much does the magneto sphere really matter?

Or are fission byproducts just that low energy when it comes to flipping bits?