fsck

Check and repair filesystems

high risk

interactive breakdown — edit the command and press Explain
$ 
⚠ Risks & cautions
Safer / dry-run alternatives
fsck -n <device>Dry run
What it does

Front-end for filesystem checkers (fsck.ext4, fsck.xfs …).

Common flags
FlagMeaning
-nDo not make changes
-yAssume yes to all prompts
-fForce
-ACheck all in fstab
Examples
fsck -n /dev/sdb1Dry run · explain & risk-check →
fsck -f /dev/sdb1Force check (unmounted) · explain & risk-check →
Related
e2fsck mount smartctl
Open the full explainer →More in Disks & Filesystems

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