What Is a Disk Partition? Types and How to Create One on Linux

A partition is a separate section of a disk that the operating system treats as its own unit. Partitioning lets you keep the operating system, user data and swap apart, use different file systems or install more than one OS. This guide explains partition tables and types, then shows how to create a disk partition in Linux step by step.

Why partition a disk?

• Separate system files from data, so reinstalling the OS keeps data safe.
• Stop log files or user data from filling the root file system.
• Use different file systems or mount options for different purposes.
• Dual-boot several operating systems.

Partition tables: MBR vs GPT

GPT is the modern standard. Use it for new systems unless you must support very old hardware.

Primary, extended and logical partitions

On MBR disks, you can have at most four primary partitions. To get more, one of them can be an extended partition, which holds several logical partitions. GPT does not need this workaround.

Partition naming in Linux

• SATA and SAS disks: /dev/sda, partitions /dev/sda1, /dev/sda2.
• NVMe drives: /dev/nvme0n1, partitions /dev/nvme0n1p1.
• Virtual disks: often /dev/vda or /dev/xvda.

Step-by-step: create a partition

In this example, /dev/sdb is a new, empty disk. Warning: partitioning the wrong disk destroys data, so check carefully with lsblk.

1. List disks

lsblk
sudo fdisk -l

2. Create a GPT partition table and partition with parted

sudo parted /dev/sdb --script mklabel gpt
sudo parted /dev/sdb --script mkpart data xfs 0% 100%

Alternatively, use fdisk /dev/sdb interactively: press g for a new GPT table, n for a new partition, accept the defaults and press w to write.

3. Create a file system

sudo mkfs.xfs /dev/sdb1
# or: sudo mkfs.ext4 /dev/sdb1

4. Mount the partition

sudo mkdir -p /data
sudo mount /dev/sdb1 /data
df -h /data

5. Mount it automatically at boot

Find the UUID with blkid /dev/sdb1, then add a line to /etc/fstab:

UUID=your-uuid-here  /data  xfs  defaults,nofail  0 0

Run sudo mount -a to test. The nofail option lets the system boot even if this disk is missing.

Common file systems

Partitions vs LVM

Plain partitions are simple, but resizing them is hard. LVM adds a flexible layer on top, so you can grow volumes online. See how to create an LVM partition.

Related guides

• How to create a swap partition
• File system management

Sources

• The Linux man-pages project

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