I know the server doesn't run Windows, but think of it like windows update. installing new files, programs, or operating system configurations.
doing things like that usually require no other activity, and reboots along the way.
in a real world network IT usually has a test lab with a miniature version running where they run the updates and test everything out first. Skuzzy I know has multiple different systems on a test network just for looking into bugs reported in game.