The goal of this page is to offer advice and strategy on partitioning a Linux system.

Required partitions

Overview

The easiest partitioning scheme, on a non-GPT disk, is simply a root partition and a swap partition.

Name

Size

swap

size of RAM

/

the rest of the disk

If the disk is GPT type (this can be checked via the "sudo parted -l" command), you must also add a BIOS-Boot or an EFI partition depending on the boot mode of your BIOS.

Name

Size

BIOS-boot or EFI

see below

swap

size of RAM

/

the rest of the disk

On some computers, a separate /boot partition may also be required.

See paragraphs below.

Root partition (always required)

  • Mount point: /
  • Type: Linux type (generally EXT4)
  • Description: the root partition contains by default all your system files, program settings and documents.
  • Size: minimum is 8 GB. It is recommended to make it at least 15 GB. Warning: your system will be blocked if the root partition is full.

Swap (very recommended)

  • Mount point: none
  • Type: SWAP
  • Description: see SwapFaq.

  • Size: size of your RAM.

Separate /boot (sometimes required)

Some computers can't see boot files (/boot) if located far (>100GB) from the start of the disk. This is why it is sometimes necessary to create a separate /boot partition at the start of the disk. Remark: don't use the same /boot for several Linux distributions, as it may mix up their kernels. See this tutorial if you want to create a separate /boot after installing Ubuntu.

Name

Size

/boot

250MB ~ 1GB

swap

at least size of RAM

/

minimum 8 GB, at least 15 GB recommended

BIOS-Boot or EFI partition (required on GPT disks)

If you want to install Ubuntu on a GPT disk (you can check it via the 'sudo parted -l' command), you will need either an EFI partition (if your BIOS is set up in EFI mode) or a BIOS-Boot partition (if your BIOS is set up in Legacy mode).

BIOS-Boot partition:

  • Mount point: none
  • Type: no filesystem
  • Description: the BIOS-boot partition contains GRUB 2's core. It is necessary if you install Ubuntu on a GPT disk, and if the firmware (BIOS) is set up in Legacy (not EFI) mode. It must be located at the start of a GPT disk, and have a "bios_grub" flag.
  • Size: 1MB.

EFI partition:

  • Mount point: /boot/efi (no need to set up this mount point as the installer will do it automatically)
  • Type: FAT (generally FAT32)
  • Description: the EFI partition (also called ESP) contains some boot files. It is necessary if the firmware (BIOS) is set up to boot the HDD in EFI mode (which is default on more and more modern, > year 2011 computers). It must be located at the start of a GPT disk, and have a "boot" flag.

  • Size: 100~250MB

Optional partitions

Optionally, some other partitions can be created for specific usages. Be careful, these partitions reduce the flexibility of your disk space, they must be considered only if you are sure not to fill completely your root partition (which would block your system).

Partition for sharing data with Windows, MacOS... (optional)

  • Mount point: /media/thenameyouwish
  • Type: to share data with Windows, choose NTFS. To share data with MacOS, choose HFS+. To share data with another Linux system, choose EXT4.
  • Description: other operating systems (Windows, MacOS..) cannot read nor write in the Ubuntu partitions, but Ubuntu can read and write in any partition. If you want to share files between Ubuntu and the other systems, it is recommended to create a data partition. It is not recommended to share files directly into the Windows system partition (eg files may be overwritten by hibernation).
  • Size: as you wish

Separate /home (optional)

  • Mount point: /home
  • Type: Linux type (generally EXT4)
  • Description: see HomeFolder. When your hard disk is big enough, a separate /home allows to separate your settings (and also your data if you don't use a data partition, see previous paragraph) from the rest of the system. A separate /home does not allow to share data with Windows nor MacOS (see previous paragraph).

  • Size: as you wish

More Complex Schemes

For more information on what various directories are used for, see The Linux Filesystem Hierarchy.

More complex schemes could involve creating a separate partition for any number of the default folders used by Ubuntu. System critical folders are important to protect, and since drives, and / or partitions do fail, it is often useful to have your file system broken down into as many small parts as possible. This can be over done however. Installing every core directory to its own partition could cause a noticeable degradation of performance.
Bearing that in mind, the following directories should NEVER be placed in their own separate partitions:

Name

Description

/bin

This directory stores the system wide executables that are accessible by most users.

/sbin

This directory holds the executables used for core system functions, and used by the system administrator
to maintain the system. See Note Below

/proc

This is a system use directory containing process information. Almost never accessed by a user.

/dev

This directory contains system created links to your installed hardware, and like /proc is almost never accessed directly.

Note about /sbin

It can be argued, and reasonably so, that moving this directory to its own partition is a wise choice. If any of your partitions or drives should fail, then this directory / partition will be the one that most likely contains the tools you will need to repair it. So while moving this would decrease performance marginally, it could also be considered a wise move.

Sizes For Alternative Schemes

On a six month old installation of Ubuntu 10.04.3 LTS the disk usage could resemble something like this: (examples taken from my own system with many extra packages installed)

Actual

Name

Size

Recommended Partition Size

/home

179.5 GB

Everything not used elsewhere, or separate drive.

/usr

7.6 GB

10 GB

/var

988.2 MB

2 GB

/lib

599.9 MB

5 GB

/boot

137.1 MB

250 MB

/opt

95.3 MB

500 MB to 5 GB This directory is not used by mainline software packages, but mostly from packages coming from the universe repositories. If you do not use the universe repositories often, you probably will not need much space here.

/etc

18.8 MB

250 MB

/sbin

7.8 MB

250 MB

/bin

6.5 MB

250 MB

/dev

876.0 KB

DO NOT PARTITION

/srv

200 KB

Unless you plan on installing web served data here, or are using a Server version of Ubuntu, this will not often need to be larger than 100 MB. If you are running a server, or plan to expand it yourself, plan ahead when sizing this.

/tmp

88 KB

This can get fairly large, but not larger than your swap space as a rule, so size this to match /swap

/mnt

8 kB (do not partition)

This is just an empty directory that serves as a mount point for temporary file systems, e.g. a rarely used network filesystem.

/media

8 kB (do not partition)

This contains subdirectories that are mount points for removable media like CDs and USB flash drives.

The above recommendations assume you are using large modern hard drives and can afford the space.

Space Requirements

Absolute Requirements

The required disk space for an out-of-the-box Ubuntu installation is said to be 15 GB. However, that does not take into account the space needed for a file-system or a swap partition.

It is more realistic to give yourself a little bit more than 15 GB of space. Give yourself 15-25 GB to have some space left for actually doing things. If your file-system is full to the brim, you will feel some performance loss.

A certain percentage of an ext3 file-system is dedicated to root, as a way of preventing a rogue process from filling the disk to the point that the system is unusable. This dedicated portion is 5% by default. Also, the anti-fragmentation strategies used by Linux file-systems require that the disk is not close to full. A rule of thumb is to keep them less than 90% full.

Installation on a small disk

(This section is out-of-date & may need research for sizes) During a normal install, the installer copies the packages from the CD to the hard drive (in addition to actually installing them). If you are short on disk space before you install, you can tell the installer not to use extra disk space. The packages take up about xxx Mb. You will be able to install a full Ubuntu system with less than xx GB of hard drive space.

At the installation prompt (just after you boot from CD) type:

linux archive-copier/copy=false


DiskSpace (last edited 2017-09-02 19:35:04 by ckimes)