WD My Cloud prevents my displays to go to sleep and screen savers to work


Since I have my WD My Cloud 6TB Ethernet connected to my Mac mini via my SpeedTouch Router, I am experiencing this problem:

My displays refuse to go to sleep and screen savers don’t work.

I got the proof that WD My Cloud is the culprit by using the following command line in Terminal:

pmset -g assertions

Result is:

Assertion status system-wide:
ChargeInhibit 0
NoDisplaySleepAssertion 0
CPUBoundAssertion 0
EnableIdleSleep 1
NoIdleSleepAssertion 0
DisableInflow 0
DisableLowPowerBatteryWarnings 0
ExternalMedia 1

Listed by owning process:
15: ExternalMedia value=255 named: “com.apple.powermanagement.externalmediamounted”

When using this command line, WD My Cloud was the only one disk connected to my Mac.

Do you have a solution or a workaround?

Many thanks in advance for your valuable suggestions, tips or advices!


If you disconnect the drive, does the computer goes to sleep mode?

I havent seen this particular case on a Mac.


Thank you very much for replying.

My daughter (“ninjacdm”) signed in but I wrote the post.


The answer is yes.

When the WD My Cloud is disconnected everything goes back to normal.