Linux checking file system failed

How to Use ‘fsck’ to Repair Linux File System Errors

Linux Filesystems are responsible for organizing how data is stored and recovered. One way or another, with time, the filesystem may become corrupted and certain parts of it may not be accessible. If your filesystem develops such inconsistency it is recommended to verify its integrity.

This can be completed via a system utility called fsck (file system consistency check), which checks the root file system automatically during boot time or ran manually.

In this article, we are going to review the fsck command and its usage to help you repair Linux disk errors.

When to Use fsck Command in Linux

There are different scenarios when you will want to run fsck. Here are a few examples:

• The system fails to boot.
• Files on the system become corrupt (often you may see input/output error).
• The attached drive (including flash drives/SD cards) is not working as expected.

fsck Command Options

The fsck command needs to be run with superuser privileges or root. You can use it with different arguments. Their usage depends on your specific case. Below you will see some of the more important options:

• -A – Used for checking all filesystems. The list is taken from /etc/fstab .
• -C – Show progress bar.
• -l – Locks the device to guarantee no other program will try to use the partition during the check.
• -M – Do not check mounted filesystems.
• -N – Only show what would be done – no actual changes are made.
• -P – If you want to check filesystems in parallel, including root.
• -R – Do not check the root filesystem. This is useful only with ‘ -A ‘.
• -r – Provide statistics for each device that is being checked.
• -T – Does not show the title.
• -t – Exclusively specify the Linux filesystem types to be checked. Types can be comma-separated lists.
• -V – Provide a description of what is being done.

Run fsck Command to Repair Linux File System Errors

In order to run fsck, you will need to ensure that the partition you are going to check is not mounted. For the purpose of this article, I will use my second drive /dev/sdb mounted in /mnt .

Here is what happens if I try to run fsck when the partition is mounted.

To avoid this unmount the partition using.

Then fsck can be safely run with.

Understanding fsck Exit Codes

After running fsck, it will return an exit code. These codes can be seen in fsck’s manual by running:

# man fsck 0 No errors 1 Filesystem errors corrected 2 System should be rebooted 4 Filesystem errors were left uncorrected 8 Operational error 16 Usage or syntax error 32 Checking canceled by user request 128 Shared-library error

Fsck Repair Linux Filesystem

Sometimes more than one error can be found on a filesystem. In such cases, you may want fsck to automatically attempt to correct the errors. This can be done with:

The -y flag, automatically “yes” to any prompts from fsck to correct an error.

Similarly, you can run the same on all filesystems (without root):

How to Run fsck on Linux Root Partition

In some cases, you may need to run fsck on the root partition of your system. Since you cannot run fsck while the partition is mounted, you can try one of these options:

We will review both situations.

Force fsck Upon System Boot

This is relatively easy to complete, the only thing you need to do is create a file called forcefsck in the root partition of your system. Use the following command:

Then you can simply force or schedule a reboot of your system. During the next bootup, the fsck will be performed. If downtime is critical, it is recommended to plan this carefully, since if there are many used inodes on your system, fsck may take some extra time.

After your system boots, check if the file still exists:

If it does, you may want to remove it in order to avoid fsck on every system boot.

Run fsck in Rescue Mode

Running fsck in rescue mode requires a few more steps. First, prepare your system for reboot. Stop any critical services like MySQL/MariaDB etc and then type.

During the boot, hold down the shift key so that the grub menu is shown. Select “Advanced options”.

Then choose “Recovery mode”.

In the next menu select “fsck”.

You will be asked if you wish to have your / filesystem remounted. Select “yes” .

You should see something similar to this.

You can then resume normal boot, by selecting “Resume”.

Conclusion

In this tutorial, you learned how to use fsck and run consistency checks on different Linux filesystems. If you have any questions about fsck, please do not hesitate to submit them in the comment section below.

I am a bachelor in computer science and a Linux Foundation Certified System Administrator. Currently working as a Senior Technical support in the hosting industry. In my free time I like testing new software and inline skating.

Each tutorial at TecMint is created by a team of experienced Linux system administrators so that it meets our high-quality standards.

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37 thoughts on “How to Use ‘fsck’ to Repair Linux File System Errors”

fsck from util-linux 2.38.1 fsck.ext2: Bad magic number in super-block while trying to open /dev/SDA /dev/SDA : the super-block could not be read or does not describe a valid ext2/ext3/ext4 filesystem.

If the device is valid and it really contains an ext2/ext3/ext4 filesystem (and if not swap or ufs or something else), then the superblock is corrupt, and you might try running e2fsck with an alternate superblock:

# e2fsck -b 8193 or e2fsck -b 32768

Found a dos partition table in /dev/SDA. When I try to run the e2fsck commands it gave, it shows sh: syntax error: unexpected newline. And then when I try to unmount /dev/SDA it can’t unmount because it’s an invalid argument? I’m a total beginner at Linux and I really don’t know what to do now Reply

Capitalization and spelling matter on the shell. Device names are never capitalized (so sda, not SDA). unmount should be umount, too. Reply

I updated to the newest version of Ubuntu, now it will not boot. I get the BusyBox black screen and when I used the exit command, here’s the output: /init: line 866: logsave: not found
Failure: File system check of the root filesystem failed
The root filesystem in /dev/sda6 requires a manual fsck But when I attempt to do so, I get a text file busy error. How can I fix this? Reply

Good morning, happy new year to you. Thank you for the article and your time spent on this website your time spent doing this is very much appreciated by me. I am using a laptop and ran a disk check using the smart control application which stated errors were found. Although I deleted the partition and reformatted the drive the errors remained which made me curious about error checking and cyclic redundancy checks which lead me to do a little research on physical drive checks and more detailed analysis. Doing searching online drove me here and to the FSCK command which even though I had wiped the drive still showed a wealth of errors (As I ran it without the -y flag initially), your article provided some clarity I was missing and made me wonder if some of these errors are reached because there is still junk data left on the drive because I have not low-level formatted it. So now I am running the command as ‘sudo fsck -y -c /dev/sdb’ Now it will search for errors, fix them as found, and display ongoing progress… Which begs the question… If I low-level formatted this drive by overwriting it with zero, would these errors then be wiped free? And if that is true, then the error that may still be found would be from smart control querying the device bios to see if it’s detected possible hardware failure (As the drive would now be wiped completely clean of any software issues) which means that fsck is really only untangling crosslinked files/sectors/clusters, etc. Forgive the stupid questions, I am not well educated on computer drives from a hardware perspective, or a read/write/data perspective so I am aware I’m ignorant and most articles I’ve read only give so much in-depth information. In any case, I am going to let this command run in its entirety and see what the outcome is. Thank you for your time. Thank you for the article. Reply

Does Linux (ubuntu) install run fsck before installing? or format automatically “note” the problematic sectors on the new partitions? I try to install Ubuntu and always ran into disc problems How to force a correction before the install? Reply

Источник

unixforum.org

FILESYSTEM CHECK FAILED! (Смена времени угробила систему. )

FILESYSTEM CHECK FAILED!

Сообщение STROGOS » 10.11.2009 02:05

Итак, попадаюсь на эту гадость второй раз. Первый раз поменял время в биосе, второй раз через sudo date —set=»гггг-мм-дд чч:мм» или как то так. Отмотал оба раза на 2 часа назад ибо системные часы спешили на 2 часа. Во втором случае перевелись и биосовские на целых 4 часа назад (хз чего).

Итак, при следующей загрузке системы я вижу следующую картину. В том месте где обычно проверятеся файловая система написано [FAILED] а ниже куча текста, который что то гонит про то, что последний раз система была монтирована тогда то, а щас такое то время. Потом рамочка из знаков ****************** озаглавненная как FILESYSTEM CHECK FAILED а в ней напсано, что мол все плохо и либо нажимай Ctrl + D или вводи пароль рута и потом команду mount -o — remount,rw / и после этого написать волшебное слово exit и система сама перезагрузится и все будет прекрасно. Естественно написание вышеназванных команд и нажатие контралдэ мне ниразу не помогало, что вызвало обильный поток нецензурностей в сторону того, кто придумал, что бы из за смены времени систему нельзя было загрузить. ФС везде ext3, корень и хоум. Есть еще 3 гб свап. Все что нагуглил это Filesystem check failed (в итоге переустановка), http://bbs.archlinux.org/viewtopic.php?pid=333790 (только куча болтовни) и http://archlinux.org.ru/arch_forum/viewtop. =527&p=4116 (в итоге репеустановка). Так что это за Г**НО?

И как мне теперь быть? В чем причина этой проблемы? Сижу щас c live kubuntu.

Источник

Arch Linux

Hi,
I have been getting a filesystem check error since yesterday now and am unable to start Arch. Upon googling and searching the arch fora, I came upon some advice which I tried which has not worked yet. Hence the new post.

Basically, I was attempting to print something off and accidentally chose a printer that was not connected to my laptop. After half a minute or so, it repeatedly started giving me notifications that the printer was not connected. in excess of 200 messages that the printer was not working which continued to pop up despite me canceling the print job. The whole system got really sluggish (for the first time in the last year) and I had to restart the laptop upon which the boot messages appear.
It gets to the point where its loading the various filesystems. It mounts root and says it fine. Then it says

/dv/sda3: clean, 171642/915712 files, 1837167/3662820 blocks /dev/sda2 is mounted. /dev/sda5 is mounted. Filesystem check failed. Please repair manually and reboot. Note that the root file system is currently mounted readonly. To remount it read-write type: mount -n -o remount ,rw / When you exit the maintenance shell the system will reboot automatically.

In my system,
/dev/sda3 is root
/dev/sda2 is boot
/dev/sda5 is home

I tried fsck which tells me that home and boot are still mounted.
So I booted up using an Ubuntu Live CD and checked and repaired each file system which it successfully did. Upon rebooting into Arch, I am getting the same message.
I have not installed anything new and had upgraded the whole system a few days before the problem started.
Not sure where to go from here.
Any help, please
Thanks

Last edited by samsom (2010-01-24 22:42:41)

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