As you know OS X checks all mounted hard disks before doing certain tasks. For example sometimes when I open a web page in Safari, the beach ball starts up and before every sleeping external HD is awakened, Safari doesn't do anything. This happens a lot on other various tasks and like me, if you have many external drives, which do sleep without the control of OS X, you wait several seconds every now and then for simple tasks. Now this is hard drive check. Is there a way to disable it?