Linux fsck.minix Command with Practical Examples

Introduction

In this lab, we will explore the fsck.minix command, which is used to check and repair Minix file systems, one of the earliest file system types used in Linux. We will learn how to use this command to verify the integrity of a Minix file system and, if necessary, repair any inconsistencies found. The lab will cover the basic usage of fsck.minix, including creating a Minix file system, checking its integrity, and repairing any issues that may arise.

Linux Commands Cheat Sheet

Skills Graph

Introduction to the fsck.minix Command

In this step, we will explore the fsck.minix command, which is used to check and repair Minix file systems. Minix is a Unix-like operating system, and its file system is one of the earliest file system types used in Linux.

The fsck.minix command is part of the Linux file system utilities and is used to verify the integrity of a Minix file system and, if necessary, repair any inconsistencies found.

Let's start by checking the version of the fsck.minix command:

fsck.minix --version

Example output:

fsck.minix from util-linux 2.38

The fsck.minix command has several options that allow you to customize its behavior. Some of the most common options include:

• -a: Automatically repairs the file system without prompting the user.
• -r: Interactively repairs the file system, prompting the user for confirmation.
• -v: Enables verbose output, providing more detailed information about the file system check and repair process.

To check the file system of a Minix partition, you can use the following command:

sudo fsck.minix /dev/sda1

Replace /dev/sda1 with the appropriate device name for your Minix partition.

The fsck.minix command will analyze the file system and report any issues found. If the file system is found to be corrupted, the command will offer to repair it.

Checking and Repairing Minix File Systems

In this step, we will learn how to use the fsck.minix command to check and repair Minix file systems.

First, let's create a Minix file system on a loopback device:

sudo dd if=/dev/zero of=minix.img bs=1M count=10
sudo mkfs.minix minix.img

This will create a 10 MB Minix file system image named minix.img.

Now, let's mount the Minix file system and create some files and directories:

sudo mount -t minix minix.img /mnt
sudo touch /mnt/file1.txt
sudo mkdir /mnt/dir1
sudo umount /mnt

To check the file system, we can use the fsck.minix command:

sudo fsck.minix minix.img

Example output:

minix.img: clean

The output indicates that the file system is clean and does not require any repairs.

Next, let's intentionally corrupt the file system by removing the superblock:

sudo dd if=/dev/zero of=minix.img bs=1 count=1024 conv=notrunc

Now, let's try to check the file system again:

sudo fsck.minix minix.img

Example output:

minix.img: Superblock is invalid, trying backup blocks...
minix.img: Root inode is not a directory, fixing.
minix.img: Inode 2 has wrong mode, fixing.
minix.img: Inode 2 has wrong size, fixing.
minix.img: Inode 2 has wrong block(s), fixing.
minix.img: Inode 2 has wrong timestamps, fixing.
minix.img: Inode 2 has wrong owner/group, fixing.
minix.img: File system repaired.

The output shows that the fsck.minix command detected the corruption and automatically repaired the file system.

Finally, let's mount the repaired file system and verify the contents:

sudo mount -t minix minix.img /mnt
ls -l /mnt

Example output:

total 0
-rw-r--r-- 1 root root 0 Apr 13 11:22 file1.txt
drwxr-xr-x 2 root root 0 Apr 13 11:22 dir1

The file and directory we created earlier are still present, indicating that the file system was successfully repaired.

Practical Examples of Using fsck.minix

In this final step, we will explore some practical examples of using the fsck.minix command.

Checking a Minix File System on a Loopback Device

Let's start by creating another Minix file system on a loopback device:

sudo dd if=/dev/zero of=minix2.img bs=1M count=10
sudo mkfs.minix minix2.img

Now, we can check the file system using the fsck.minix command:

sudo fsck.minix minix2.img

Example output:

minix2.img: clean

The output indicates that the file system is clean and does not require any repairs.

Checking a Minix File System on a Physical Device

If you have a physical device with a Minix file system, you can use the fsck.minix command to check it. Assuming your Minix partition is /dev/sda1, you can run the following command:

sudo fsck.minix /dev/sda1

This will check the Minix file system on the /dev/sda1 partition.

Repairing a Corrupted Minix File System

Let's intentionally corrupt the Minix file system we created earlier and then use fsck.minix to repair it:

sudo dd if=/dev/zero of=minix2.img bs=1 count=1024 conv=notrunc
sudo fsck.minix minix2.img

Example output:

minix2.img: Superblock is invalid, trying backup blocks...
minix2.img: Root inode is not a directory, fixing.
minix2.img: Inode 2 has wrong mode, fixing.
minix2.img: Inode 2 has wrong size, fixing.
minix2.img: Inode 2 has wrong block(s), fixing.
minix2.img: Inode 2 has wrong timestamps, fixing.
minix2.img: Inode 2 has wrong owner/group, fixing.
minix2.img: File system repaired.

The output shows that the fsck.minix command detected the corruption and automatically repaired the file system.

Summary

In this lab, we learned about the fsck.minix command, which is used to check and repair Minix file systems. We started by exploring the basic usage of the command, including checking the version and understanding the common options. We then learned how to create a Minix file system on a loopback device, mount it, and use the fsck.minix command to check and repair the file system. The lab provided practical examples to demonstrate the usage of the fsck.minix command, which is an essential tool for maintaining the integrity of Minix file systems.

Linux Commands Cheat Sheet