Jettison: Tom's Mac Software Pick

Ensure Your Mac's External Drives Are Ejected Properly With Jettison

Jettison menu bar item
Screen shot courtesy of Coyote Moon, Inc.

Jettison, from the folks at St. Clair Software, is one of those very handy utilities that should have been part of OS X. Jettison eliminates the need to manually eject connected drives or SD cards when putting your Mac to sleep.

Although Jettison may find its most frequent use with those of us who use portable Macs, it works just fine with desktop Macs as well.


  • Works automatically to eject external drives.
  • Can be triggered by simply closing your Mac’s lid.
  • Can also be triggered by selecting Sleep.
  • Prevents sleep until all external devices are ejected.
  • Remounts externals when your Mac wakes up.


  • All or nothing; can’t specify which externals to automatically eject when going to sleep.

Jettison is designed to make packing up and going easier for those of us with portable Macs. How often have you been at your home or office working on your Mac when you remembered that you needed to take your Mac with you to a meeting or event?

The normal sequence of events is to manually unmount all of the external drives that are connected to your Mac, and eject any SD card that is attached. Then, if everything unmounted successfully, you can close the lid or use the Apple menu to put your Mac to sleep.

Of course, what usually happens is that you can’t unmount at least one of the externals because it's in use; it's likely that Time Machine is running a backup, or you have an app open that is working with a document stored on an external drive. Most of the time, you probably don’t even notice that the drive in question never unmounted, and you close the lid, disconnect the cables from your Mac, and take off. You don't discover the bad news until you return home or to the office; a drive is now corrupt from not being disconnected properly.

That's where Jettison comes in. It can’t prevent you from physically disconnecting a drive prematurely, but it can automate the process of going to sleep, ejecting all external drives, and letting you know that the drives have all been ejected properly and that sleep has been started.

Using Jettison

Jettison installs as a menu bar item that provides easy access to ejection options, the ability to easily mount drives, and options for sleep. In fact, the eject and mount options are so easy to get at from the menu bar you may never delve into Disk Utility for these capabilities again.

Selecting Jettison from the menu bar reveals the following options:

  • Eject External Disks Now
  • Eject and Sleep Now
  • Sleep Now
  • Remount Ejected Disks Now
  • Eject
  • License
  • Mount
  • Preferences
  • About Jettison
  • Quit Jettison

The first three items are the Jettison services you will likely use the most. Eject External Disks Now is exactly what it sounds like; selecting this option will cause all attached external drives to be ejected. Jettison will display a status message indicating that the ejection is proceeding. If a Time Machine backup is occurring that uses one of the external drives, Jettison will cancel the backup to allow the ejection to occur. Once all the externals are ejected, a notification sound will be played (you can choose the sound in the Jettison preferences), and an alert will be displayed.

Eject and Sleep Now provides the same ejection services as Eject External Disks Now, plus, once the ejection completes with no issues, your Mac will be put to sleep. This same eject and sleep process is performed if Jettison is active and you close the lid of a portable Mac or choose sleep from the Apple menu.

Sleep Now forces your Mac to sleep without first ejecting any external drives. This mimics the way that Macs were originally put to sleep, and can be useful when you just need to control access to your Mac while you're on a coffee break.

Remount Ejected Disks Now does what you'd expect; any drives that were previous ejected by Jettison are immediately remounted. This is much quicker then manually opening Disk Utility to remount the drives.

The Eject and Mount commands in Jettison allow you to select a single device to eject or mount. You can even use the mount command to mount normally hidden volumes, such as the Recovery HD partition.

Final Thoughts on Jettison

Jettison is a Mac software pick because it's well designed, easy to use, and addresses a real-world need to be able to safely and quickly disconnect your portable Mac from your externals so you can take it with you wherever you need to go.

I can’t tell you how many times I've seen the “disk was not ejected properly” message when reconnecting an external drive to my MacBook Pro, all because I unplugged the drive before shutdown or sleep was completed. With Jettison, I know by the confirmation sound that all of my drives have been properly ejected, and that I won't risk any data loss by unplugging them once I hear the confirmation.

Jettison also works well for any desktop Mac connected to external drives. The many menu items within Jettison can easily take care of all drive eject and mounting needs.

If you've ever seen the dreaded “disk was not ejected properly” message, you may want to consider giving Jettison a try.

Jettison is available from the Mac App store for $4.99. A demo is available from St. Clair Software’s web site.

See other software choices from Tom's Mac Software Picks.

Published: 11/14/2015