Chosen Solution
I can’t adjust my disk sleep settings for my secondary hard drive in El Capitan. Any ideas what’s causing this? I only use my secondary platter HD for storageand I don’t need to have it spinning 24/7 when I am on my laptop. Even though I typed “sudo pmset -a disksleep 2” into the terminal I find that it defaults to 10 upon reboot. Any ideas on how to fix it?
Your only option is to dismount the drive. You might give this app a try: M3 Drive Mounter. We don’t use dual drive setups so I can’t tell you if this utility will help.
This is technically an unauthorized repair from Apple, and the settings that Apple has “hardwired” into the firmware are specifically for disk drives for CDs and DVDs, not hard drives.
