Originally published at: AppBITS: Jettison Solves macOS Disk Ejection Annoyances - TidBITS
One of the longest-standing aspects of the Mac user experience is the necessity of ejecting disks before turning them off or unplugging them. Initially, this meant literally ejecting floppy disks from their drives, but Apple retained the term even after adding non-removable media.
All About Eject
The need for the Eject command arises from two reasons. First, if there are open files on a disk, macOS refuses to let you eject it because doing so might result in data loss. Second, the Eject command forces macOS to flush any data cached in memory and write it to the physical disk, ensuring that everything is saved and preventing file corruption.
Despite all the advances in macOS since 1984, we still need to virtually eject disks before physically disconnecting them. Today, you can select a disk and choose File > Eject (Command-E) or drag one or more disks to the Trash icon, which helpfully changes to an Eject icon so no one is led to think the disk or its contents will be deleted. If there are multiple volumes on a single physical disk, macOS allows you to eject just the selected one or, as is often desirable, all of them.
It’s also still possible to encounter a situation where a file remains open on a disk such that macOS won’t let you eject it. Sometimes the solution is simple—just quit the offending app. Other times, macOS doesn’t identify the app, leaving you unsure of what to quit or if quitting is even an option, especially when a low-level process has the file open. You can throw caution to the wind and power the drive down or unplug it unceremoniously, but macOS always chides you for such uncouth behavior.
If macOS cannot eject the disk or identify the rogue programs, it allows you to force eject the disk—a software override that bypasses macOS’s safety checks but still flushes cached data, making it safer than simply unplugging. If that makes you too nervous, your only recourse is to shut down your Mac, disconnect the disk while everything is powered off, and then turn the Mac back on. You can also restart and unplug it between quitting all applications and macOS booting up again, though that requires more precise timing.
I’ll admit, I occasionally forget to eject a disk before disconnecting it or inadvertently unplug the wrong disk while working behind my Mac. However, I’ve never experienced any file or disk corruption that I could attribute to that action. Still, it’s never a good idea to cut power to a drive or unplug it without first ejecting it.
Jettison That Disk!
For the most part, I don’t have trouble ejecting disks. Sometimes, when I try to eject the duplicate that SuperDuper makes of my internal boot disk every night, the backup disk’s icon disappears from my desktop, but I’m still chided for failing to eject “Disk Name – Data” when I disconnect it. I feel that it’s unfair because I had ejected the disk, but I can’t reproduce the problem reliably.
Regardless, many people experience recurring issues with external disks. When leaving the house with your laptop, you can close the lid and disconnect all its cables without worry… except for those connected to external disks, which remain mounted even when the laptop is asleep. Others find themselves in situations where macOS seems incapable of ejecting disks for no good reason. And still more people store working data or media on external drives that they want to mount and dismount in different situations.
Those who need more control over their external disks than macOS provides should consider Jettison, available for $6.95 from St. Clair Software, which provides a plethora of features designed to simplify working with external disks. It’s a menu bar utility that’s entirely up front about its capabilities, which you can try for free for 15 days. It runs on macOS 10.13 High Sierra and later, and is compatible with both Intel-based and Apple silicon Macs.
Easily accessed commands in Jettison’s menu enable you to:
- Eject all your external disks at once
- Eject all your external disks and then put the Mac to sleep
- Sleep your Mac
- Eject individual volumes
- Mount available volumes
- Remount disks that you previously ejected
Jettison’s Settings window provides extensive control over when and how disks are ejected, reported to the user, and remounted.
These settings allow Jettison to:
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- Automatically eject disks before system sleep
- Automatically eject disks after the display turns off
- Automatically eject disks before logout, restart, and shutdown
- Control what sort of disks will be ejected: hard disks and SSDs, DVDs and CDs, disk images, network disks, and SD cards
- Show a progress window while ejecting and remounting, since both tasks can sometimes take longer than seems reasonable
- Display notifications after ejecting and remounting
- Let you use hotkeys for ejecting external disks, ejecting and then sleeping, and remounting
- Automatically remount disks upon wake-up
- Eject specific internal disks along with external disks
- Avoid ejecting specific disks
- Avoid remounting specific disks
A few of these may need more explanation. For instance, why would you want to eject your disks automatically after the display turns off? Since the display may go black before the Mac goes to sleep, some people found themselves disconnecting disks when they shouldn’t have because the screen was off while the Mac was still awake.
Also, what’s up with ejecting disks before logout, restart, and shutdown, given that macOS already ejects most disks in the latter two cases? One reason for that option is that you might have an encrypted disk containing private data that you don’t want to be accessible to other accounts on your Mac. Another reason arises if you have a removable media drive and want to eject whatever disc is in there before shutting down.
Jettison developer Jon Gotow tells me something that’s not immediately obvious. When Jettison is set to eject disks before sleep, it automatically quits Music and Photos in case the user is storing their libraries on an external disk. When the Mac wakes up again, Jettison relaunches those two apps. You can find similar tweaky details about how Jettison works (and what might prevent it from working as expected) in the Jettison FAQ.
Jettison can’t (or at least won’t) eject disks containing open files, but it tries to help you identify and quit the associated apps.
Everyone has different needs and circumstances, but if you’ve found yourself forgetting to eject disks before disconnecting them from your laptop or fussing to eject and remount disks regularly, Jettison may be your new favorite utility. Give it a try.