So my favorite console on OS X is iTerm2. When I’m working with multiple servers, one of the most useful features is “Broadcast Input” (BI).
BI lets you type into one terminal session, but send those keystrokes to more than one session. This can be all of the tabs in the iTerm window, all of the panels in one tab, or some of the panels across multiple tabs. This is both a very powerful feature, in that it can allow you to configure many servers at the same time, and very dangerous in that it can allow you to inadvertently destroy many servers at the same time.
With great power… Moving on.
All of these options are found under the “Shell” menu, Broadcst Input, like so:
You’ll notice that I have “Show Background Pattern Indicator” selected. This is not selected by default. Trust me, you’ll want it on. With this on, it stripes the background of your consoles when broadcast input is on. The behavior is a bit odd though, as it turns on striping in all consoles when choosing “Broadcast Input to All Panes in All Tabs” and “Broadcast Input to All Panes in Current Tab” but only in active consoles when you choose “Toggle Broadcast Input to Current Session”. Just messes with your head, really, but it is a great visual indicator of when you could potentially do something very destructive to your environment.
Now for the best part. To turn it off, just “Send Input to Current Session Only.”
Hope this helps!