External drives can still work even if it looks like they are idle.
It’s easy to eject an external SSD or HDD from your computer without thinking as soon as the file transfer is complete. You may have been doing this for years without serious repercussions, leading you to assume that properly disabling external drives is just old computer advice that has been around since it was relevant. But in fact, it is still important to properly disable external drives before removing them from your computer.
Even after the file transfer is complete, your computer doesn’t always open its business with your external drive. Beneath the surface, your operating system can still handle tasks like writing cached data from memory and sorting file directories. On macOS, for example, features like Time Machine and Spotlight still engage external drives in the background, even after the transfer is over. If you take a few seconds to eject an external drive, it tells your computer to finish any process before turning it off. Doing so reduces the risk of data corruption and incomplete file transfers.
What happens if you don’t let go of external demands
Many times nothing happens when you turn off a drive without pulling out, but the action always carries a risk. The negative results of not properly ejecting an external drive are largely the same across Windows, Mac, and Linux. If a transfer is in progress, either in the foreground or in the background, the drive pulls the process incomplete and files potentially corrupt. What’s worse, file corruption can be silent, so you could delete the original file thinking it was copied, only to find later that the version on your expensive flash drive is corrupted.
Even pulling out an external drive without ejecting carries the risk of file system corruption. A file system is your drive’s record of what is where and what is what. Unannounced removal can leave the drive with half-updated information about its files, which is one of the reasons why Windows prompts you to scan and fix a drive when you turn it back on. The famous “Disk Not Ejected Properly” on Mac is not a sign of data loss; it is simply a warning. The real problem occurs when the drive disappears in the middle of writing, such as during a backup.
In rare cases, neglecting to disconnect your external drive can lead to partition table damage. The partition table is like the drive’s table of contents, which operating systems use to navigate its sections. Partition table damage causes your computer to see the drive as unallocated or uninitialized, making it unusable until it’s fixed.
Is it ever safe to unplug an external drive without ejecting it?
There are times when it is safe to unplug a drive without properly ejecting it, especially when the drive is idle. “Idle” means that no apps are using it, none of its files are open and no transfer is happening. The caveat is that “Idle” to you doesn’t always mean idle to your computer; it can initiate background processes without you knowing. Given the time it takes to confirm if it is actually idle, ejecting or dismounting is faster (and safer).
How safe it is to suddenly disconnect external drives depends on your operating system. During the lifetime of Windows 10, Microsoft made the quick removal policy the default setting for removable drives. This reduces the risk of an unsafe ejection error at the expense of performance. You can change this setting for each drive by right-clicking on it kick off button and select Disk Management. Here, click on your removable drive in the lower list, select Propertiesthen click on policies Tab and choose between Quick removal in the Better performance.
On a Mac, background processes like Time Machine backups and Spotlight indexing can continue to work after you’re done transferring files, so proper ejection is important there. Linux is the most dangerous of the three because it relies heavily on write caching to improve performance. It may look like a transfer is being made when it takes a few seconds to complete, so pulling out the cable may leave data in memory instead of being properly written to the drive.
Some newer drives have built-in protection against sudden disconnection that helps protect against data loss or corruption. But these functions can fail, so don’t trust them blindly. Your best bet is to always disable or unmount the external drive before removing it. This only takes a moment, and the OS will warn you when an operation is complete so you don’t have to guess.