That's a big "yeah but". You can't rate limit the io. That's huge and the percona tool and LHM offer ways to keep io under control. Along with that you have to

That's a big "yeah but". You can't rate limit the io. That's huge and the percona tool and LHM offer ways to keep io under control. Along with that you have to pay attention to the live schema update matrix in the docs; many things will upgrade with out locking but require copying the table and this will blast your IO. In addition even with the tools some changes require exclusive table locks. It needs it for a short period of time but if it can't get it because of a long running transaction , queue of transactions, and etc it can block everything up.