How to Mount File Systems in Linux

File system mounting is a fundamental operation in Linux, allowing users to access and manage different file systems from various storage devices. Whether connecting a hard drive, USB drive, or network share, mounting is necessary to make these resources available to your system. 

This tutorial will guide you through the process of mounting file systems in Linux, including mounting manually with the mount command, automating mounts using /etc/fstab, and troubleshooting common issues.

Common File Systems in Linux

Linux supports a variety of file systems, each suited for different needs. Some of the most commonly used file systems include:

• ext4: The default file system for many Linux distributions.
• NTFS: Typically used for Windows systems.
• FAT32/exFAT: Used for USB drives and other portable storage.
• XFS: Ideal for large data storage solutions.

Understanding the type of file system is crucial when mounting storage devices, as the necessary options and commands may differ.

Mounting a File System with the mount Command

The mount command is used to manually mount file systems in Linux. The basic syntax is as follows:

sudo mount [OPTIONS] <source> <mount_point>

• <source>: The device or file system to be mounted, such as /dev/vdc1.
• <mount_point>: The directory where the file system will be mounted, such as /mnt.

On Hostman servers, disk names follow the format vd*, where * is replaced by a letter from a to z. The letter corresponds to the disk’s number in the system.

The primary disk always contains the operating system and is named vda. The second disk, vdb, is reserved for cloud-init. So, in this guide, we will focus on working with the vdc disk. 

If you are using this guide for virtual machines from another provider, make sure to verify the correct disk names beforehand.

Identify the File System

First, you need to identify the available disks and partitions. You can use the following command to list them:

lsblk

This command displays the block devices along with their mount points, helping you identify the target device.

Create a Partition

If you need to create a new partition, you can do so using fdisk. Replace /dev/vdc with your target disk:

sudo fdisk /dev/vdc

Follow the prompts to create a new partition (for instance, /dev/vdc1). You will typically use the following commands within the fdisk utility:

• n: to create a new partition
• p: to select primary
• Specify the partition number and size as required
• w: to write changes to the disk

Create a File System

Once the partition is created, format it with a file system. Here’s how to create an ext4 file system on the newly created partition:

sudo mkfs.ext4 /dev/vdc1

Mount the File System

To mount the file system, use the following command, specifying the mount options:

sudo mount -o barrier=0 /dev/vdc1 /mnt/mydrive/

Verify the Mount

Finally, check if the file system has been mounted successfully by using the df command:

df -h

This command displays all mounted file systems and their disk usage, allowing you to confirm that your new file system is correctly mounted.

Unmounting a File System

To unmount a file system, use the umount command followed by the mount point or device name:

sudo umount /mnt/mydrive

Automating Mounts with /etc/fstab

Mounting file systems manually every time you boot can be tedious. Fortunately, Linux provides a way to automate the process through the /etc/fstab file. The /etc/fstab file contains information about disks and partitions that should be automatically mounted at boot.

1. Open the /etc/fstab File: Use a text editor to open the /etc/fstab file:

sudo nano /etc/fstab

2. Add a New Entry: Add an entry to the file in the following format:

<device> <mount_point> <file_system_type> <options> <dump> <pass>

    Example:

echo “/dev/vdc1 /mnt/mydrive ext4 barrier=0 0 0 1” >> /etc/fstab

• <device>: The partition, for example, /dev/vdc1.
• <mount_point>: The directory where the file system will be mounted.
• <file_system_type>: The type of file system, for example, ext4.
• <options>: Mount options, for example, defaults.
• <dump>: Used for backups, typically set to 0.
• <pass>: The file system check order during boot.

3. Test the New Entry: After saving the file, test the changes by using the mount command to mount all file systems in /etc/fstab:

sudo mount -a

Example /etc/fstab Entry:

/dev/vdc1 /mnt/mydrive ext4 defaults 0 2

This entry mounts the ext4 partition /dev/vdc1 to /mnt/mydrive at boot.

Checking Mounted File Systems

To view all currently mounted file systems, use the following commands:

• df: This command provides information about disk usage and mounted file systems:

df -h

• mount: Displays a list of all mounted file systems:

mount | grep "^/dev"

Both commands can be useful for verifying whether a file system is properly mounted and accessible.

Troubleshooting File System Mounting Issues

Mounting issues can arise due to various factors, such as incorrect device paths, unsupported file systems, or permission problems. Here are some common issues and troubleshooting tips:

mount: wrong fs type, bad option, bad superblock

This error can occur if the wrong file system type is specified. Verify the correct file system type with lsblk -f and try mounting again:

sudo mount -t ext4 /dev/vdc1 /mnt/mydrive

Permission Denied

Ensure you have the necessary permissions to mount the device. Use sudo to gain administrative privileges:

sudo mount /dev/vdc1 /mnt/mydrive

Device Not Found

If the device cannot be found, verify its path using lsblk or fdisk -l. The device name may change based on how the storage is connected.

Automated Mounting Fails

If file systems fail to mount automatically at boot, verify the /etc/fstab entry for syntax errors. Run the following to test the /etc/fstab file:

sudo mount -a

If the issue persists, review system logs using dmesg for more detailed error messages.

Conclusion

Mounting file systems in Linux is an essential task for accessing storage devices. By mastering the mount command, automating mounts with /etc/fstab, and troubleshooting common issues, users can efficiently manage their file systems. This tutorial covered all the necessary steps for mounting a file system, from basic commands to troubleshooting errors.