System administration command. Call the filesystem checker for the appropriate system type to check and repair unmounted filesystems. If a filesystem is consistent, the number of files, number of blocks used, and number of blocks free are reported. If a filesystem is inconsistent, fsck prompts before each correction is attempted. fsck's exit code can be interpreted as the sum of all conditions that apply:
Errors were found and corrected.
Errors were found but not corrected.
fsck encountered an operational error.
fsck was called incorrectly.
A shared library error was detected.
Pass all subsequent options to filesystem-specific checker. All options that fsck doesn't recognize will also be passed.
Serial mode. Check one filesystem at a time.
Specify the filesystem type. Do not check filesystems of any other type.
Check all filesystems listed in /etc/fstab. The root filesystem is checked first.
Display completion (progress) bar.
Suppress normal execution; just display what would be done.
Meaningful only with -A: check root filesystem in parallel with other systems. This option is potentially dangerous.
Meaningful only with -A: check all filesystems listed in /etc/fstab except the root filesystem.