fsck - file system check

Use fsck to check and repair a file system. **The file system must be unmounted when being check and repaired to prevent corruption! **

The root file system can not be unmounted and checked. Two possible options to check the system are:

• Force the Root Filesystem to use fsck during reboot, The Geek Stuff covers this well in, How to Force Check Root Filesystem using fsck During Reboot. A summary of key commands:
• The Root file system is automatically checked at certain intervals. To check this: “sudo tune2fs -l /dev/sda1 | grep -i check”.
• To force a recheck at the next reboot, create the file forcefsck. At the next reboot a fsck will be performed and the forcefsck file removed. Commands:
  • “cd /”
  • “sudo touch forcefsck”
• Boot the system to a rescue file system. From the rescue file system the main boot drive may then be checked with fsck. (Further details not given.)

• To check current mounted disks use “df -h”
• To check current disks use “sudo fdisk -l”. (This is a disk partition command. Be careful with use.)
• To check current disks use “sudo parted -l”. (This is a disk partition command, more modern than fdisk. Be careful with use.)
• To check directory size use “sudo du --max-depth=1 --all -h”
• The filesystem boot file is /etc/fstab, “sudo vim /etc/fstab”. (Be careful with editing this.)