I had El Capitan installed on my computer, and due to problems related to system constantly going busy, and displaying rotating beach ball on every move, I had to move back to Mavericks. But surprisingly, that too was not helping out. I couldnot understand the problem, as I had used Mavericks in the past without any problem. Ultimately researching things for some days I decided to stop spotllight completely. ( Till now I was making spotlight off partially only). Here is the command on Terminal I used : sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.metadata.mds.plist I understand, this kills a very important mac's feature, but I was tired of watching that beach ball rotating. After using the above command, I got positive results, and I am no longer getting the rotating beach ball, and constant freezing. However, I doubt, may be it's some coincidence. I want to know, if anyone else on El Capitan ever tried the same to stop spotlight completely, and got results that solved their problem, of system getting constantly busy ? I want to upgrade to El Capitan again, and probably will make the spotlight off, untill a better solution arrives. So in case anyone get their problem solved, please share your experience.