The Safe Removal icon, which appears after removing devices, is something a computer user encounters on a daily basis but chooses to ignore its significance.
If you are asked to remove a USB while transferring data to it, you will refuse to do so. Such an action could destroy the data being written to the disk.
However, even when your USB is not in active use, the sudden removal of the drive could still destroy your data. This occurs because of the caching process used by most operating systems. Thus, the information is not written immediately to the USB device. Instead, it is possible that some information is stored in your computer's RAM.
When you issue a copy command, the operating system waits for a series of requests to complete and then fulfills those requests all at once. Thus, it is possible to corrupt some data if you abruptly remove a USB drive.
Why do Linux, macOS, and Windows behave differently?
This behavior is more common on MacOS and Linux operating systems. Why not on Windows? Because Microsoft’s operating system disables the cache feature for drives it considers removable. Windows gives you an option to improve performance (always select it) and quick removal. This option is accessible via Device Manager > Disks > Disk Name > Properties > Policies.
On the other hand, Mac and Linux use caching on almost all drives. The same behavior is observed in Windows, if you choose the option for better performance. So Windows will cache data before writing it to the removable drive.
If you are using a computer with Windows, you may not see the Safe Removal icon. However, Windows is not very clear and there are different processes underway in the background. Thus, it is possible to lose data even with the fast removal setting.
Therefore, as a precautionary measure, always manually eject all your USB drives. It doesn't matter which operating system you use, make it a habit.
