How to Mount and Unmount Drives in Linux

What is mounting

Linux does not give drives letters. A drive is attached to a folder, called a mount point. After mounting, the files of the drive appear inside that folder.

Find the available drives

lsblk

sudo fdisk -l

Check the file system

sudo blkid

Method 1: Mount by hand

Step 1: Create a mount point

sudo mkdir /mnt/drive1

Step 2: Mount the drive

sudo mount /dev/sda2 /mnt/drive1

Use the same folder name in both commands.

Step 3: Check the mount

df -h

mount | grep sda2

Method 2: Mount a specific file system

sudo mount -t ext4 /dev/sda2 /mnt/drive1

For a FAT32 USB drive:

sudo mount -t vfat /dev/sdb1 /mnt/mydrive

For NTFS (install ntfs-3g if needed):

sudo mount -t ntfs-3g /dev/sdb1 /mnt/mydrive

Method 3: Mount at boot with /etc/fstab

Step 1: Find the UUID

sudo blkid

Step 2: Edit /etc/fstab

sudo nano /etc/fstab

Add a line like this (use your UUID and mount point):

UUID=1234abcd-12ab-34cd-56ef-1234567890ab  /mnt/drive1  ext4  defaults  0  2

The fields are: device, mount point, file system, options, dump flag and fsck order.

Step 3: Test the file

sudo mount -a

No error means the line is correct. A bad fstab line can stop the system from booting, so always test before a reboot. Add nofail to the options for drives that may be missing.

Unmount a drive

sudo umount /mnt/drive1

You can also use the device:

sudo umount /dev/sda2

(The command is umount, with no "n".)

If the device is busy

The error target is busy means a program or your shell is using the drive. Leave the folder (cd ~), then find what uses it:

sudo lsof +f -- /mnt/drive1

or

sudo fuser -vm /mnt/drive1

Stop those programs and unmount again. As a last step you can use a lazy unmount, which detaches the drive as soon as it is free:

sudo umount -l /mnt/drive1

Quick recap

• lsblk finds the drive, mount DEVICE FOLDER mounts it, umount unmounts it.
• Use the UUID in /etc/fstab to mount at boot.