How to mount disks and partitions in Linux

Mounting disks and partitions in Linux attaches additional storage devices to the active filesystem so applications and users access data through regular directories instead of raw devices. Consistent mounts keep extra system, data, and backup volumes reachable in predictable locations, whether backed by virtual disks, internal drives, or removable media.

The Linux storage stack exposes each disk as a block device such as /dev/sda and partitions such as /dev/sda1. The mount command binds a filesystem from such a device to a mount point directory, while tools like lsblk and blkid enumerate devices, report filesystem types, and show UUID values that provide more stable identifiers than raw device names.

Most mounting operations require elevated privileges because incorrect options or entries in /etc/fstab can prevent services from starting correctly or even block boot. Choosing a suitable mount point, deciding whether the mount is temporary or persistent, and validating configuration changes with mount -a before rebooting reduces the risk of losing access to stored data.

1. Open a terminal with a user account that has sudo privileges.
2. Identify the disk or partition that requires mounting by listing block devices.

   $ lsblk
   NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
   loop0    7:0    0  55.4M  1 loop /snap/core18/1944
   loop1    7:1    0  55.4M  1 loop /snap/core18/1932
   loop2    7:2    0 217.9M  1 loop /snap/gnome-3-34-1804/60
   loop3    7:3    0   219M  1 loop /snap/gnome-3-34-1804/66
   loop4    7:4    0  64.8M  1 loop /snap/gtk-common-themes/1514
   loop5    7:5    0    51M  1 loop /snap/snap-store/518
   loop6    7:6    0  62.1M  1 loop /snap/gtk-common-themes/1506
   loop7    7:7    0    51M  1 loop /snap/snap-store/498
   loop8    7:8    0  31.1M  1 loop /snap/snapd/10707
   loop9    7:9    0  31.1M  1 loop /snap/snapd/10492
   sda      8:0    0    20G  0 disk 
   ├─sda1   8:1    0     1M  0 part 
   ├─sda2   8:2    0   513M  0 part /boot/efi
   └─sda3   8:3    0  19.5G  0 part /
   sdb      8:16   0    20G  0 disk 
   └─sdb1   8:17   0    20G  0 part 
   sr0     11:0    1  1024M  0 rom

3. Determine the filesystem type and UUID of the target partition.

   $ blkid /dev/sdb1
   /dev/sdb1: UUID="ccab0f8d-3b5b-4189-9da3-23c49159c318" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="c088a647-01"

4. Create a directory under the home directory to act as the mount point if it does not already exist.

   $ mkdir disk

5. Temporarily mount the disk or partition to the mount point to test access.

   $ sudo mount -t ext4 /dev/sdb1 disk
   [sudo] password for user:

   Replace ext4 with the filesystem type reported by blkid when mounting non-ext4 filesystems.

6. Verify that the disk or partition is mounted at the expected path.

   $ df -h
   Filesystem      Size  Used Avail Use% Mounted on
   tmpfs           391M  1.8M  389M   1% /run
   /dev/sda3        20G  7.1G   12G  39% /
   tmpfs           2.0G     0  2.0G   0% /dev/shm
   tmpfs           5.0M     0  5.0M   0% /run/lock
   tmpfs           4.0M     0  4.0M   0% /sys/fs/cgroup
   /dev/sda2       512M  7.8M  505M   2% /boot/efi
   tmpfs           391M  112K  391M   1% /run/user/1000
   /dev/sdb1        20G   45M   19G   1% /home/user/disk

7. Unmount the previously mounted partition after testing access.

   $ sudo umount /dev/sdb1

8. To mount the disk automatically at startup, edit the /etc/fstab file with elevated privileges.

   $ sudo vi /etc/fstab

   An incorrect entry in /etc/fstab can prevent Linux from booting until the file is corrected.

9. Add an entry in /etc/fstab for the disk or partition using the chosen device identifier.

   /dev/sdb1       /home/user/disk ext4    defaults        0       0

   For more robust configuration, prefer the UUID value from blkid as shown in How to mount disk partitions using UUID in Linux instead of the raw /dev path.

10. Apply the configuration by mounting all filesystems defined in /etc/fstab.

    $ sudo mount -a

11. Confirm that the disk or partition is mounted according to the /etc/fstab entry.

    $ df -h
    Filesystem      Size  Used Avail Use% Mounted on
    tmpfs           391M  1.8M  389M   1% /run
    /dev/sda3        20G  7.1G   12G  39% /
    tmpfs           2.0G     0  2.0G   0% /dev/shm
    tmpfs           5.0M     0  5.0M   0% /run/lock
    tmpfs           4.0M     0  4.0M   0% /sys/fs/cgroup
    /dev/sda2       512M  7.8M  505M   2% /boot/efi
    tmpfs           391M  112K  391M   1% /run/user/1000
    /dev/sdb1        20G   45M   19G   1% /home/user/disk