Partitioning

Table of Contents

Understanding Disk Partitioning in Linux Installation

Partitioning is the step where you decide how your disk is divided into separate logical sections (partitions) before installing Linux. In this chapter you’ll focus on what you actually need to know and choose during installation, without going deep into advanced storage topics.

Why Partition at All?

During installation, the system needs:

A place to store the operating system files
A place for your personal files
Optional areas for swap, boot data, or encryption

Partitioning controls how these areas are separated on your disk. This affects:

How easy it is to reinstall the system without losing personal data
How safe your data is from system errors
How multiple operating systems can share the same disk

Basic Terms You Will See in Installers

When using a graphical or text installer, you’ll often see these terms:

Disk / Device: The whole physical drive, e.g. /dev/sda, /dev/nvme0n1
Partition: A section of a disk, e.g. /dev/sda1, /dev/sda2
Filesystem: The format used on a partition, e.g. ext4 (commonly used for Linux), ntfs (Windows), vfat (FAT32)
Mount point: The directory where a partition is attached into the Linux filesystem (e.g. /, /home, /boot)
Free space / unallocated: Space on the disk not yet assigned to a partition

You usually do not need to work directly with fdisk or parted at installation time; the installer provides a GUI or menu-based partitioning tool built on top of these.

Partitioning Schemes: Automatic vs Manual

Most Linux installers offer two broad approaches:

Automatic (Guided) Partitioning

Typical options you’ll see:

“Erase disk and install Linux”
“Use entire disk”
“Guided – use entire disk with LVM”
“Guided – use entire disk and set up encrypted LVM”

Characteristics:

Installer chooses how many partitions to create and their sizes
Safest for beginners if you don’t need dual-boot
Fast and usually sensible defaults

When to use it:

You’re installing Linux on a computer where Linux will be the only OS
You’re okay with the installer erasing the entire disk
You don’t care about custom layout yet

Manual (Custom / Something Else) Partitioning

Names vary:

“Manual partitioning”
“Something else”
“Custom storage configuration”

Use this when:

You want to dual-boot with Windows or another Linux
You need specific sizes for /, /home, or swap
You want to re-use existing partitions
You want to keep a data partition untouched

Manual mode lets you:

Create / delete / resize partitions
Choose mount points like /, /home, /boot
Choose filesystems (e.g. ext4)
Decide whether to format each partition

Partition Table Types: MBR vs GPT (Just Enough to Choose)

The disk has a partition table describing how partitions are arranged.

For beginners, you usually just need to recognize two names:

MBR (msdos): Older style

Max ~2 TB per disk
Maximum 4 primary partitions (workaround with “extended” partitions)

GPT: Modern style (recommended)

Supports large disks (multi-TB)
Many more partitions
Required for some UEFI setups

On modern systems with UEFI firmware, installers normally choose GPT automatically. Unless you have an old machine or a specific reason, accept the default.

Typical Partitions in a Linux Install

You don’t have to memorize many layouts. For a simple desktop or laptop installation, you generally only need 2–3 partitions:

Root (/) – required
Swap – optional but recommended in many setups
Home (/home) – optional but very useful

Other partitions like /boot, /boot/efi, or separate /var are more specialized and usually handled automatically by the installer in guided modes.

1. Root Partition (`/`)

Purpose: Holds the core of the OS: system programs, libraries, configuration, etc.
Mount point in installer: /
Filesystem: Typically ext4
Size guideline for a beginner desktop:

Minimal usage: 20–30 GB
Comfortable: 40–60 GB
Very large apps / games / containers: 80+ GB

Beginner recommendation: If you don’t want to think too much, give / at least 40 GB so you don’t run out of space quickly.

2. Swap Area

Swap is disk space used when RAM is full or for some power-saving features like hibernation.

You may see:

A dedicated swap partition
A swap file on an existing partition

Many modern installers default to a swap file, so you might not need to create a separate swap partition manually. But if you do:

Size guidelines (rough):

If RAM ≤ 4 GB: swap = 2–4 GB
If RAM 8–16 GB: swap = 2–8 GB
If using hibernation: aim for about size of RAM (or a bit less, depending on usage)

If unsure and using guided partitioning, just accept the default.

3. Home Partition (`/home`)

Purpose: Stores your personal files and per-user settings
Mount point: /home
Why have it separate?

You can reinstall Linux (format /) without losing personal data (/home)
Easier to share a data area among multiple Linux installations

Beginner rule of thumb:

If you create a separate /home, give it all remaining space after / and swap.

If you prefer simplicity, you can skip separate /home and just have everything under a single / partition; personal data will simply live inside /home on that partition.

Step-by-Step: A Simple Manual Layout Example

Imagine you have a 500 GB disk and want:

Linux only (no dual-boot)
A separate /home
Swap partition

A reasonable manual layout:

EFI System Partition (ESP) (if using UEFI, often created automatically)

Size: 300–500 MB
Filesystem: FAT32
Mount point: /boot/efi (installer will know this)
Usually do not format it if dual-booting with Windows; ok to format on Linux-only installs.

Root (/)

Size: 40–60 GB
Filesystem: ext4
Mount point: /
Mark to format

Swap

Size: 4–8 GB (depends on RAM and hibernation)
Type: swap

Home (/home)

Size: all remaining space (e.g. ~430 GB)
Filesystem: ext4
Mount point: /home
Mark to format (unless reusing an existing /home carefully)

If using a BIOS/legacy system with MBR and no UEFI, you might skip the EFI partition and just have /, swap, and /home.

Dual-Boot Considerations (At Partition Level Only)

If you’re dual-booting with Windows or another OS, partitioning becomes more delicate. High-level things to keep in mind:

Never format the Windows partition (commonly NTFS, often the largest one labeled “OS” or similar).
Use Windows tools first to shrink the Windows partition if needed, leaving unallocated space.
In the Linux installer’s manual partitioning:

Use the unallocated space to create /, swap, and optionally /home.
Ensure you select the correct target drive for the bootloader (often the same disk where Windows lives).

As a beginner, always double-check labels, sizes, and filesystems before clicking “Format” or “Install”.

Filesystem Choice (Just What You Need Here)

For basic installations, you can almost always choose:

ext4 for Linux partitions (/, /home, /var if you ever create it)
swap type for swap partitions
Leave existing NTFS or FAT32 partitions as they are if they belong to Windows or are data drives

Other filesystems (XFS, Btrfs, etc.) are suitable for more advanced setups and are covered elsewhere.

Common Installer Options You’ll Encounter

When editing or creating a partition in the installer, you typically set:

Use as: e.g. Ext4 journaling filesystem, Swap area
Mount point: e.g. /, /home, /boot, /boot/efi, or leave empty for non-Linux data
Format?: checkbox or option to erase existing contents

Safe beginner rules:

For new Linux-only installs on a blank disk:

Format all new Linux partitions.

For dual-boot where you are reusing Windows and data partitions:

Do not format those existing non-Linux partitions.

If reusing an existing /home from a previous Linux installation:

Usually set mount point /home
Carefully decide whether to avoid formatting to keep data (requires understanding of users and permissions, covered later).

Minimal “Don’t-Panic” Checklist Before You Click Install

Before you start the actual installation:

Confirm which disk you are using (e.g. /dev/sda vs /dev/sdb if multiple disks).
Check that the partition with mount point / is:

Large enough (≥20–30 GB, ideally more)
Marked for ext4 (or your chosen filesystem)
Marked to format (for fresh install)

Check that you have swap, either:

A swap partition, or
The installer says it will create a swap file

If you created /home:

It has mount point /home
It uses ext4 (or another Linux filesystem)

For dual-boot:

Windows partition is still listed, not marked to format
EFI System Partition (if present) is not incorrectly formatted unless you intend a clean Linux-only system

If all of that looks correct, you’re usually safe to proceed with installation.

Summary

Partitioning is about how your disk is divided for Linux and other operating systems.
Beginners can rely on guided partitioning when using a disk for Linux only.
Manual partitioning is needed mainly for dual-boot or custom layouts.
For a simple manual layout, aim for:

/ (root): 40+ GB, ext4
swap: a few GB, or use installer defaults
optional /home: remaining space, ext4

Always double-check disk, sizes, mount points, and which partitions will be formatted before starting the installation.

`/` (root)

`/home`

Swap

Comments

Please login to add a comment.

Don't have an account? Register now!