Mac OS X Tip

After migrating over to my new iMac, I realized that my external media drives were spinning down after a period of time and would go to sleep.  This was bugging me because it would cause a delay in the system when I tried to access music or photos.  I could not get this to change, no matter what I tried in the system preferences under power settings.  I know this was one of those set it and forget it type of things because I didn’t have this problem on the old G5.  After doing some digging I found the answer and I thought I’d share it in case someone else is having the problem.  The power settings for external drives can be manipulated via the terminal with the command “pmset” AKA: “Power Management Settings”.   Open up the terminal (found in Applications  -> Utilities) and type the following command and a numeric value in minutes to represent the sleep time.

sudo pmset -a disksleep VALUE 

You will be asked for your password and then the settings will be in effect.  Since I did not want my discs to go to sleep at all, I chose to do a value of zero which told the system to never put the discs to sleep.  Since this is a desktop I’m not worried about saving battery life.  I ran the following command:

sudo pmset -a disksleep 0 

Problem solved!