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Tomáš Pečený
Asked: 2013-10-05 09:46:25 +0800 CST

How to use fsck in Ubuntu?

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I intend to use fsck for checking my Linux partition of the main disk, because its file system is suspicious of being 

not unmounted cleanly
by shutting down the system. I have searched in my environment variables: none of them except of PATH should control the fsck program. But the program apparently needs to be used during a boot:
:~$ fsck -V
fsck from util-linux 2.20.1
Checking all file systems.
[/sbin/fsck.ext4 (1) -- /] fsck.ext4 /dev/sda6 
e2fsck 1.42 (29-Nov-2011)
/dev/sda6 is mounted.

WARNING!!!  The filesystem is mounted.   If you continue you WILL
cause SEVERE filesystem damage.
Do you really want to continue? no
check aborted.
(There is no /forcefsck file in my root according to How do I find out if there will be a fsck during the next boot? . My etc/fstab file contains

 
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
#                
proc            /proc           proc    nodev,noexec,nosuid 0       0
# / was on /dev/sda6 during installation
UUID=1ac55d8d-c112-4bc7-9e79-921d196f9f79 /               ext4    errors=remount-ro 0       1
# swap was on /dev/sda7 during installation
UUID=54f7e314-50e2-419b-a45d-47c3058ecc00 none            swap    sw              0       0
/dev/fd0        /media/floppy0  auto    rw,user,noauto,exec,utf8 0       0

).
According to an answer to Slow reboot - understanding fsck and tune2fs I have tried tune2fs hoping that I'll get the present value of the 

max_mounts_count
parameter to be able to set it to 1 for checking the partition during the next boot. But after 
sudo rm /var/lib/update-notifier/fsck-at-reboot
and a restart I have only got a response 
:~$ tune2fs -l /dev/sda6
tune2fs 1.42 (29-Nov-2011)
tune2fs: Permission denied while trying to open /dev/sda6
Couldn't find valid filesystem superblock
. Can I use 
sudo tune2fs -l /dev/sda6
safely? Thanks.

boot

3 Answers

  1. Best Answer

    To run fsck on your harddrive you need to boot a liveCD and then run the commands with your harddrive partitions as the target.

    "There is no /forcefsck file in my root"

    -You need to create the file, it is just a blank file so run sudo touch /forcefsck and fsck will check your drive next time your reboot.

    • 8

  2. I concur with @bodhi.zazen comment here. The best way to go about checking a filesystem is to boot from live media, choose "Try Ubuntu" and then manually fsck the partition in question. For example sudo fsck /dev/ZdXY where ZdXY is the partition in question. sudo fdisk -l will give you a listing of your drives and the partitions on them. This information should be sufficient for you to determine which partition you need to check.

    • 2

  3. In addition to what other answers said, I would also point out that normally, if the root filesystem wasn't cleanly unmounted, if you just reboot, it will be automatically fsck'ed, when that status is detected during mounting.

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