Fix 'umount: target is busy'

fuser -vm shows the processes holding files open on a mounted device; close them (or stop your own shell sitting in that directory) so umount succeeds.

LinuxProcessesDiagnosticsmountLow risk

Run `fuser -vm /media/usb`, close the listed programs (often a terminal whose working directory is inside the mount), then retry `umount /media/usb`.

01Command

Command

$ fuser -vm /media/usb

02What it does

Linux refuses to unmount a filesystem while any process has files open or its working directory inside it — the classic cause is your own terminal being cd'd into the mount, or a file manager window viewing it. `fuser -vm` (or `lsof +f -- <dir>`) names the culprits so you can close them instead of blindly force-unmounting.

03Risk

RiskLow risk

Requirementspsmisc package (fuser); preinstalled on most distros

!Warning: As a last resort `umount -l` detaches the filesystem lazily, but data still being written may be lost; avoid it when a copy is in progress.

04Undo

Undo

$ null

05Sources

fuser(1) — identify processes using files or sockets
man7.org · community · 2026-09-17
Evidence: fuser -v -m DIR lists processes using the mounted filesystem
umount(8) — unmount file systems
man7.org · community · 2026-09-17
Evidence: describes the EBUSY 'target is busy' condition

Last verified: 2026-09-18 · Category: System & Settings

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