Avoiding Spotlight to spin up external drive I have Mac Mini with an external hard drive. The external drive is indexed with Spotlight. Whenever I use Spotlight to start an app on the local machine, the external drive spins up, because obviously Spotlight wants to check the spotlight files on the external drive for search hits. The drive makes an audible noise, and stays running for some five minutes until it idles to a stop.

Is there any way around this, apart from disabling Spotlight or disconnecting the drive? Obviously, I understand that Spotlight must access the spotlight files to check for search hits, and can't tell the difference if I want to launch an app or find a file, when I just type "Sa" for Safari.

The only cure I could think of was if the entire spotlight database was cached in memory, or was placed on the local hard drive, or if I used a different hotkey for finding files and launching apps.
Yes, this is pretty annoying behavior, especially if you have multiple hard drives connected to your Mac, and to my knowledge there is no way to prevent Spotlight from doing it.

Fortunately, most app launchers such as LaunchBar, Alfred, Butler, Quicksilver, etc. maintain cached file databases, so they don't spin up all your drives whenever you use them to launch an app or to search for a file. They also have a ton of other useful features. I personally would recommend Alfred or LaunchBar.