Linux mlabel Command with Practical Examples

Introduction

In this lab, you will learn how to use the mlabel command in Linux to create, change, and remove volume labels on file systems. The mlabel command provides a simple and efficient way to manage volume labels, which can be useful for organizing and identifying storage devices. You will start by understanding the purpose and syntax of the mlabel command, and then explore how to create and manage volume labels using various options. The lab covers advanced mlabel command scenarios, providing practical examples to help you become proficient in using this disk and file system utility.

Linux Commands Cheat Sheet

Skills Graph

Understand the Purpose and Syntax of the mlabel Command

In this step, you will learn about the purpose and syntax of the mlabel command in Linux. The mlabel command is used to create, change, or remove volume labels on file systems.

First, let's explore the basic syntax of the mlabel command:

sudo mlabel [options] [volume]

The [options] can include:

• -s: Display the current volume label
• -c: Create a new volume label
• -r: Remove the current volume label
• -i: Ignore errors

To see the current volume label of a file system, you can use the following command:

sudo mlabel -s /dev/sdb1
Example output:
Volume label is "My Data"

This command displays the current volume label of the /dev/sdb1 file system.

To create a new volume label, you can use the -c option:

sudo mlabel -c "My New Label" /dev/sdb1
Example output:
Volume label set to "My New Label"

This command sets the volume label of the /dev/sdb1 file system to "My New Label".

To remove the current volume label, you can use the -r option:

sudo mlabel -r /dev/sdb1
Example output:
Volume label removed

This command removes the volume label from the /dev/sdb1 file system.

Remember, the mlabel command operates on the file system level, so you need to specify the volume or device you want to work with.

Create and Manage Volume Labels Using the mlabel Command

In this step, you will learn how to create and manage volume labels using the mlabel command.

First, let's create a new volume label for a file system:

sudo mlabel -c "My Data Volume" /dev/sdb1
Example output:
Volume label set to "My Data Volume"

This command sets the volume label of the /dev/sdb1 file system to "My Data Volume".

Now, let's verify the current volume label:

sudo mlabel -s /dev/sdb1
Example output:
Volume label is "My Data Volume"

The mlabel -s command displays the current volume label of the specified file system.

To change an existing volume label, you can use the -c option again:

sudo mlabel -c "Updated Data Volume" /dev/sdb1
Example output:
Volume label set to "Updated Data Volume"

This command updates the volume label of the /dev/sdb1 file system to "Updated Data Volume".

Finally, let's remove the volume label:

sudo mlabel -r /dev/sdb1
Example output:
Volume label removed

The mlabel -r command removes the volume label from the specified file system.

Remember, the mlabel command operates on the file system level, so you need to specify the volume or device you want to work with.

Explore Advanced mlabel Command Options and Scenarios

In this step, you will explore some advanced options and scenarios for the mlabel command.

One advanced option is the -i or --ignore-errors flag, which allows you to ignore any errors that may occur during the volume label operation. This can be useful if you're working with a file system that may have issues or if you want to force a label change even if there are potential problems.

Let's try an example where we intentionally create an invalid volume label:

sudo mlabel -c "My Invalid Label*" /dev/sdb1
Example output:
mlabel: Volume label "My Invalid Label*" is not valid

As you can see, the mlabel command refuses to set the volume label because it contains an invalid character (*). However, we can use the -i option to ignore this error:

sudo mlabel -i -c "My Invalid Label*" /dev/sdb1
Example output:
Volume label set to "My Invalid Label*"

Now, the volume label has been set, even though it contains an invalid character.

Another advanced scenario is using the mlabel command on a mounted file system. While this is generally not recommended, as it's better to manage volume labels on unmounted file systems, you can still do it if necessary:

## Mount the file system
sudo mount /dev/sdb1 /mnt

## Change the volume label
sudo mlabel -c "Mounted Volume" /mnt
Example output:
Volume label set to "Mounted Volume"

## Unmount the file system
sudo umount /mnt

In this example, we first mount the /dev/sdb1 file system to the /mnt directory, then change the volume label using the mlabel command, and finally unmount the file system.

Remember, as with any file system operations, it's important to be cautious and ensure that you're working with the correct devices and file systems to avoid data loss or corruption.

Summary

In this lab, you first learned about the purpose and basic syntax of the mlabel command in Linux, which is used to create, change, or remove volume labels on file systems. You explored how to display the current volume label, create a new volume label, and remove an existing volume label using various mlabel options. Then, you practiced managing volume labels, including creating a new label, verifying the current label, and changing an existing label. Finally, you explored advanced mlabel command options and scenarios, such as handling errors and using the command in different file system contexts.

Linux Commands Cheat Sheet