“I just wait a couple of seconds before unplugging a drive…”
“I never safely eject a disk, and I’ve never had a problem…”
“I waited for the light to go off before I pulled the plug, and everything looks fine…”
There’s a lot of different ideas about disconnecting disks, and different ideas about why (and if) it’s necessary. In reality, unplugging a drive without telling the OS is always risky.
Why Safely Remove/Safely Eject a Disk?
Most operating systems use a technique called “write caching” to maximize disk performance. Write caching is about adding delays. When an app makes a change to a file, the OS might delay this change for a short time so that it can group multiple changes together. When you “safely eject” a disk, you’re telling the OS to ensure that all these changes are completed and saved to the drive.
If you just unplug a disk without “safely ejecting,” some changes might not make it to the disk. Sometimes this causes obvious problems like missing files or even an unusable drive. Sometimes the issues can be less obvious – your disk might seem fine, but the contents of some of your files could be missing (resulting in an un-editable document, an unplayable video, etc.).
How to Safely Remove Your Disk
Different platforms have different ways to eject a disk safely.
You can safely eject a disk using either of the following methods:
- In the notification area (next to your clock), there is an icon that looks like a USB plug. Click this icon to get a list of drives connected to the computer, then click the drive you want to eject. Note that the icon might be hidden in the “overflow area”–the little up-arrow icon in the notification area.
- In File Explorer, right-click on a drive, then click “Eject.”
You can safely eject a disk using any of the following methods:
- In Finder, drag a volume to the trash can.
- In the left pane of Finder, click the eject symbol next to a disk.
- Right-click on the drive’s icon on the Desktop and select “Eject (volume name)” from the popup menu.
There are also a few utilities available that will safely eject multiple disks in one click—handy if you’re packing up your laptop. And if you’re using an OWC dock, OWC Dock Ejector will safely eject all disks connected through the dock.
Disk in Use
Sometimes when trying to eject your disk, you will receive an error telling you the “disk is in use.” This means that some app (or the OS itself) is still using the disk. If you know which application it is, you can simply close that app and try again. If you can’t tell which one is using the disk, some 3rd-party apps (such as Unlocker for Windows) can help locate it.
“Quick Removal” OS Settings
Finally, some operating systems have settings that allow you to disable write-caching (resulting in a slower disk) so you can seemingly skip “safe removal.” While this makes your drive somewhat safer, it doesn’t tell you if an app is still using it. Unplugging might still cause data to be lost.
In the end, it’s always best to safely eject your drive. It only takes a moment and helps keep your data safe.