Some people like to run hardware through extensive testing before they use it for a production machine so that they feel confident that the hardware is solid and will not have problems. Unfortunately, this is an option that is not viable for everyone. Hardware failure is a fact of life and something that is for the most part unavoidable unless you get lucky. As such, there is no way to make sure your nodes will never go down, so instead we recommend you concentrate on making sure that, if a node does go down, you can quickly recover.