Do you really have to eject a USB drive before unplugging it?

Question

Weirdo · Accepted Answer

Not always, but ejecting first is the safe habit. Since Windows 10 version 1809, external drives default to “Quick removal”, where Windows doesn't cache writes, so you can unplug directly; but if a drive has been switched to “Better performance”, pulling it out can lose data.

Microsoft's documentation says that starting with Windows 10 version 1809 the default policy for external storage is Quick removal: Windows doesn't cache write operations, which keeps the device ready to remove at any time without the Safely Remove Hardware process. The trade-off is that write performance can suffer. And of course, if you pull the drive while a file is still copying, that file won't be complete.

Microsoft also describes a Better performance policy: Windows can cache writes to the external device for speed, but you must use Safely Remove Hardware so the cached operations finish, and removing the drive without it risks data loss. The policy is set per device: in Disk Management, right-click the device, choose Properties, then Policies. From the outside you can't tell whether you or your workplace changed it.

Microsoft's support page advises always safely removing USB flash drives and external hard drives to avoid losing data: right-click the Safely Remove Hardware and Eject Media icon in the system tray, choose Eject for the device, and unplug once the “Safe To Remove Hardware” notification appears. On a Mac, select the device and choose File > Eject, click the eject button beside it in the Finder sidebar, or drag it to the Trash; if it won't eject, an app or another user is usually still using files on it.

Do you really have to eject a USB drive before unplugging it?

The Windows default: Quick removal

Switch it to “Better performance” and you must eject

How to eject