How to check disk errors in Linux

Disk errors in Linux can cause system instability and data loss. Common issues include bad sectors, disk failures, and filesystem inconsistencies. Regular checks with built-in tools help prevent these problems.

Ensure the disk is unmounted before running diagnostics. If unmounting is not possible, use a live Linux system like Ubuntu for checking.

Different tools check various aspects of disk health. Use smartctl for hardware checks, fsck for filesystem integrity, and badblocks to find bad sectors.

1. Open the terminal application.
2. List available disks in your system.

   $ lsblk
   NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
   loop0    7:0    0 55.4M  1 loop /snap/core18/1997
   loop1    7:1    0  219M  1 loop /snap/gnome-3-34-1804/66
   loop2    7:2    0 64.8M  1 loop /snap/gtk-common-themes/1514
   loop3    7:3    0 32.3M  1 loop /snap/snapd/11588
   loop4    7:4    0   51M  1 loop /snap/snap-store/518
   loop5    7:5    0 65.1M  1 loop /snap/gtk-common-themes/1515
   sda      8:0    0   20G  0 disk 
   ├─sda1   8:1    0    1M  0 part 
   ├─sda2   8:2    0  513M  0 part /boot/efi
   └─sda3   8:3    0 19.5G  0 part /
   sdb      8:16   0   20G  0 disk /mnt/data
   sr0     11:0    1 1024M  0 rom

3. Unmount the disk you intend to check.

   $ sudo umount /dev/sdb
   [sudo] password for user:

   Replace sdb with your specific disk identifier.

4. Check the disk's S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology) health status using smartctl.

   $ sudo smartctl -H /dev/sdb
   smartctl 7.2 2020-12-30 r5155 [x86_64-linux-5.11.0-16-generic] (local build)
   Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
   
   === START OF READ SMART DATA SECTION ===
   SMART Health Status: OK

   Related: How to check disk health status in Linux

5. Run fsck to check the filesystem.

   $ sudo fsck /dev/sdb
   fsck from util-linux 2.36.1
   e2fsck 1.45.7 (28-Jan-2021)
   /dev/sdb: clean, 11/1310720 files, 126322/5242880 block

6. Scan the disk for bad blocks using badblocks.

   $ sudo badblocks -v /dev/sdb
   Checking blocks 0 to 20971519
   Checking for bad blocks (read-only test): done                                                 
   Pass completed, 0 bad blocks found. (0/0/0 errors)

7. Remount the disk after completing all checks.

   $ sudo mount /dev/sdb /mnt/data