umount

Unmount filesystems

medium risk

interactive breakdown — edit the command and press Explain
$ 
⚠ Risks & cautions
Safer / dry-run alternatives
fuser -vm <mountpoint>Find processes using the mount
findmnt <mountpoint>Confirm what is mounted there
What it does

Detaches a filesystem. Fails if files are open (use lsof/fuser to find them).

Common flags
FlagMeaning
-lLazy unmount: detach now, clean up later⚠ Processes keep stale handles.
-fForce (NFS)⚠ May lose in-flight data.
-RRecursive
Examples
umount /mnt/dataUnmount · explain & risk-check →
fuser -vm /mnt/dataSee what is using it · explain & risk-check →
Related
mount lsof
Open the full explainer →More in Disks & Filesystems

Reference text is hand-written and may be incomplete — check man umount for your version. Test destructive commands on a non-production system first.