umount

umount [device or mountpoint]

Detaches ("unmounts") a previously mounted filesystem, so it can be safely removed or remounted elsewhere.

// FLAGS

-fforce unmount, for an unresponsive filesystem

-llazy unmount — detach now, clean up once nothing is using it

// EXAMPLE

umount /mnt/data — unmounts the filesystem at /mnt/data.

// GOTCHA

umount fails with "device is busy" if any process still has an open file or working directory on that filesystem — lsof or fuser can identify what's holding it open.

// RELATED COMMANDS

mount lsblk fdisk