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Systems & Data Center · Foundational

fsck

The Linux filesystem consistency check and repair utility, run on unmounted filesystems.

Definition

fsck dispatches to filesystem-specific checkers such as e2fsck for ext2/3/4. Running it on a mounted read-write filesystem can cause corruption. XFS uses xfs_repair instead. The sixth fstab field sets the fsck pass order at boot.

Example

umount /data && fsck -y /dev/sdb1 checks and auto-repairs an ext4 partition.

Exam tip

Never run fsck on a mounted filesystem; for XFS the correct tool is xfs_repair.

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