Checking disks and filesystems for errors

Linux filesystems are incredibly robust. Despite that, a filesystem can become corrupted and data can be lost. The sooner you find a problem, the less data loss and corruption you need to worry about.

Getting ready

The standard tool for checking filesystems is fsck. This command is installed on all modern distributions. Note that you'll need to run fsck as root or via a sudo.

How to do it...

Linux will run fsck automatically at boot time if the filesystem has been unchecked for a long time or there is a reason (unsafe reboot after a power glitch) to suspect it's been corrupted. You can run fsck manually.

1. To check for errors on a partition or filesystem, pass the path to fsck:

        # fsck /dev/sdb3
        fsck from util-linux 2.20.1
        e2fsck 1.42.5 (29-Jul-2012)
        HDD2 has been mounted 26 times without being checked, check forced.
        Pass 1: Checking inodes, blocks, and sizes
        Pass 2: Checking directory structure
        Pass...