OSX and External HDs

[ovbg]

Hello,
I have an external HD connected to my iMac via USB. I find it doesn't power down any more when the Mac sleeps. I have tried logging out and closing background apps but that makes no difference.
I have set in preferences "Put Hard Drives to sleep when possible" but that also makes no difference. (And Power Nap is not enabled)
Does anyone have any further suggestions?

 

[chscag]

From your post above, I gather that the hard drive at one time did power down or "sleep" when your Mac sleeps? Have you recently updated macOS? Anyway, try resetting the SMC on your Mac to see if that helps. Also, you need to consider that the not going to sleep problem may be with the hard drive itself. If you have another external hard drive to test with, that would help isolate this.

 

[brownrebecca164]

*Is it bus powered or does it have a separate power supply? And are you properly ejecting the drive before powering off your Mac?

 

[IWT]

A warm welcome to Mac-Forums, brownrebecca164. Glad to have you along.

Thank your post. May there be many more

EHDs don't need to be ejected when an iMac is put into sleep mode nor if the iMac needs to be rebooted or even shut down for a short time.

All my EHDs (Time Machine backups x 2 and 2 cloned backups, making 4 EHDs in all), remain mounted and untouched through sleep cycles, rebooting etc. The iMac's software takes care of all that.

Ian

 

[Rod]

My guess is not ejecting.