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macrumors regular
Original poster
Aug 8, 2012
I have an external drive connected to a 13Inch 2012 MBP I use as a HTPC. Even though I have deactivated "put hard drives to sleep" in power management it will spin down after a while anyway.

I have tried the application Keep Drive Spinning, it looked like it was working but the drive spun down anyway.

I have tried the terminal command sudo pmset -c spindown 0 and caffeinate. The drive still goes to sleep using theese commands.

I use 10.12.5, macOS sierra.

Any ideas on how to prevent an external USB drive to stop spinning down? I have googled but havent found anything that works in sierra apparently.


macrumors 6502a
Aug 7, 2011
It could very well be the USB -> SATA controller that's part of the external HDD that is putting the drive to sleep due to lack of activity, this would be something outside of the OS' control. A work-around would be to set up a cron or scheduler job to write something like the current time to a file on the external drive every 5-10 minutes to keep it awake.


macrumors member
Apr 4, 2016
I learned the hard way a while back that some HDD manufactures put eco settings in the drive's firmware itself, rendering the OS settings null and void. I had this problem with a Seagate drive and according to their own documentation the only way to stop it or control it in any manner was to install their software and have it running continually. First of all, bullsh*t, total bullsh*t, and second, it was Windows only software, again, total bullsh*t.
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