Master Linux Disk Partitioning and Mounting: A Step‑by‑Step Guide

Disk Partition Principle

Disk partitioning splits a physical hard‑disk into independent logical sections (e.g., sda1, sda2). Each partition appears as a separate block device, allowing isolated file systems, easier space management and data organization.

Viewing Disk Devices and Partitions

List all block devices with their size, type and mount point: lsblk Show filesystem type and UUID as well:

lsblk -f

Creating a New Partition with fdisk

Start an interactive session for the target disk (e.g., /dev/sdb) and follow the prompts:

Enter m for help.

Enter n to create a new partition.

Select partition type: p for primary or e for extended.

Specify the partition number (usually 1 for the first partition).

Provide the start and end sectors, or a size such as +10G.

Press w to write the table and exit.

fdisk /dev/sdb

Formatting the Partition

After the partition appears as /dev/sdb1, create a filesystem (ext4 in this example):

mkfs -t ext4 /dev/sdb1

Mounting the Partition

Temporary mount

Create a mount point and mount the partition:

mkdir /mnt/temp

mount /dev/sdb1 /mnt/temp

Verify with lsblk that the mount point is active.

Permanent mount

Add an entry to /etc/fstab so the partition is mounted automatically after reboot. Example line: /dev/sdb1 /mnt/data ext4 defaults 0 0 Apply the changes without reboot:

mount -a

Unmounting a Partition

Unmount by device name or by mount point:

umount /dev/sdb1

umount /mnt/data

If the device is busy, ensure no processes are using the mount point before retrying.

Deleting a Partition

Re‑enter fdisk for the disk, delete the desired partition, and write the changes: fdisk /dev/sdb Press d to delete.

Select the partition number (e.g., 1).

Confirm the deletion.

Press w to write the table and exit.