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Jettison automatically ejects external disks from your Mac before your computer goes to sleep.

Simplify those last few seconds when you grab your MacBook and run out the door. Just close the lid and Jettison will automatically eject your backup drive, iPod, or whatever is connected so you can safely unplug it. Say goodbye to "disk was not ejected properly" errors and waking your computer back up because you forgot to eject everything.

Jettison even makes sure that Time Machine backups and file server volumes are properly shut down before they're removed. Your backups and shared files are safe and more...

What's New

Version 1.4:
  • Jettison can automatically eject disks at shutdown and restart as well as when your Mac goes to sleep.
  • You can now assign hotkeys to eject disks, eject disks and sleep your Mac, and remount disks.
  • There's a new option to reload the USB driver at wakeup so that USB flash drives will remount without removing and reinserting them.
  • Previously hidden preferences more...


OS X 10.6 or later

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Jettison User Discussion

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sambear1965 Member IconComment+1

Which version is recommended? 1.3 from St.Clair Software website or 1.2.4 from Apple App Store, sorry if this is a dumb question, but why are there two versions available concurrently, Thanks!

Running 10.9.1

Reply0 replies
Version 1.3
Ken Burns Effect Member IconComment+30
Ken Burns Effect

Only costs 1.99 USD in Mac App Store!

Just bought it since my Time Machine drive crashed for not ejecting properly.

Reply1 reply
Version 1.2.4
Pablo The Innocent

Still doesn't do the job . Time Machine disk will not mount after sleep. iMac Core i7 Fusion Drive ( late 2013)

Drdul Member IconComment+448

For the most part, Jettison works, but it isn't able to eject a disk if it's "in use." As gatovadio notes below, often what qualifies as "in use" is an app that is not actively reading or writing. There's no ability to quit apps, or to run an Applescript that could quit chronic offenders. A lot of the time I end up having to manually eject one of my disks. I'm going to give unDock a try, as the new version offers more features than Jettison, even if it doesn't (yet) trigger on sleep.

Reply3 replies
Version 1.2.4

I just found that the oldie SleepWatcher is updated to work from 10.3 to 10.8. I haven't played with it but it should allow even more freedom than both these apps, with endless scripting possibilities.



Or EventScripts

St. Clair Software (Developer)

It's not safe to eject a drive while there's a file open on it, even if you're not actively reading or writing to the file at the time (and OS X will not allow it). Think of it this way: If you open a spreadsheet in Numbers and then put your Mac to sleep, when it wakes up Numbers expects to be able to read whatever data it needs to refresh its windows, save changes, etc. If the file is suddenly gone, you've got a data integrity problem.

gatovadio Member IconComment+0

It would be a nice addition to auto quit apps which are in use by some disks (media players or wallpaper switchers which don't even require me to save my work before quitting).

Reply0 replies
Version 1.2
goggles Member IconReview+5

I had a dismount problem with a external firewire hard drive, when it entered sleep, Jettison eliminated the problem completely, now I can let the computer go to sleep when ever it wants.

Reply0 replies
Version 1.2
Basharar Member IconReview+0

lifesaver for me, i was having problems with external drives connected via express card "usb3 and esata" not waking up properly with my macbook pro on time, this is a godsend!

Reply0 replies
Version 1.2
Kitmos Member IconReview+124

This works well as I often forget to unmount my drives before sleep. I wish it would also unmount my iPad but I gather that isn't possible.

Reply0 replies
Version 1.2
user icon+217
St. Clair Software
Version 1.2.4
user icon+0
Version 1.2
> 4 5


Current Version (1.x)


Downloads 14,124
Version Downloads 482
License Shareware
Date 24 Jun 2014
Platform Intel 64 / OS X / Intel 32
Price $4.95
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