How to automatically (un)mount USB drive when Mac goes to sleep?

[nielsmouthaan]

How can I automatically unmount my USB drive when my Mac goes to sleep and have it mount again when it wakes up?

I'm asking this as the drive is connected to an external display, which powers off automatically when my Mac starts sleeping. However, that disconnects the drive without ejecting it properly potentially causing damage to the drive or its volumes.

 

[duanepatrick]

If you are comfortable in installing 3rd party apps on your mac and are fully aware of the risks, try the Jettison app.

 

[nielsmouthaan]

Perfect, seems to work fine. I already developed a quick prototype myself to see if an app would be capable of doing this and that proofed to be working.

 

[nielsmouthaan]

I had some issues with Jettison as it unmounted (only) when my Mac started sleeping. I needed the volume to get unmounted when my screen(s) started sleeping instead. Unfortunately Jettison didn't allowed me to configure this.

I developed a similar app, that allows you to configure when (external) volumes should be unmounted:

• When the screensaver starts.
• When the screen is locked.
• When the screens started sleeping.
• When the system starts sleeping.

It can be found at ejectify.app for others interested in something similar.

 

[duanepatrick]

Wow. And you made a website for it. Is there any way that you can post this on App Store?

 

[nielsmouthaan]

Unfortunately not. I've managed to get unmounting work when I enable sandboxing but mounting again doesn't work, something I find crucial to the usability of the app. So simply put: Apple won't allow this app in the Mac App Store.

 

[duanepatrick]

Understandable.

 

[scgf]

Given that Ejectify lets you specify when the attached device is un-mounted, I figured it might just work where Jettison didn't. I paid up, downloaded the app, selected 'when display is turned off' and it worked! My Garmin device has never unmounted correctly unless I did it manually and I always got the error message. It isn't necessary to re-mount the Garmin device since it does its syncing within a couple of minutes of mounting and the rest of the time it charges. I am very pleased! Thank you

nielsmouthaan​

 

[nielsmouthaan]

That’s great to hear!