unmounts

Unmounts refers to the act of detaching a filesystem or storage resource that was previously mounted into a computer’s directory tree. When a filesystem is unmounted, the mount point is no longer linked to the device, and the kernel releases the associated resources. A clean unmount aims to flush pending writes and close open files so that removing a device or network share does not risk data loss or corruption.

In Unix-like systems, the standard tool is the umount command. It can unmount by specifying the mount point directory (for example, umount /mnt/usb) or the device identifier (for example, umount /dev/sdb1). Some implementations support options such as -l for a lazy unmount (detach immediately but complete cleanup later) or -f for a forced unmount in certain situations, though forcing can increase the risk of data loss if the filesystem is busy. If a mount is busy, users may need to identify processes using the mount (with tools like lsof or fuser) and close those files or terminate processes before retrying.

Platform variations exist. On macOS, diskutil unmount or diskutil unmountDisk can be used. On Windows, unmounting is typically handled via Disk Management or command-line tools like mountvol to remove a mount point, or net use to disconnect network drives. In virtualization and container environments, unmount operations are also used to detach virtual disks or shared volumes.

Common considerations include ensuring all data is synchronized, closing applications using the mount, and understanding that a forced or lazy unmount can introduce risk if the filesystem is active.