Welcome to this comprehensive guide, that will help you set up a dual boot system with a Linux OS and Windows or simply with two Linux OSs.

Warning: Before carrying on with this guide it is best that any important data is backed up in case anything were to go wrong during the setup.

DualBooting with Windows

In order to dual boot alongside Windows, we first need to create a new Linux partition by taking space from the Windows partition. It is recommended to have at least 20-25GB of free space available for most Linux installations if you plan on using it as much as you do your Windows installation. If you are just testing the distribution first and don’t want to commit as much space, then read your chosen distribution minimum requirements, although it’s best to have around 10 -15GB.

There are programs in Windows such as EaseUS partition manager that can create the free space you need, but it is highly recommended that you use the partition manager that comes with the distribution you plan to install, the reason being that this is where you will install the file system and partitions that your Linux OS needs. Most programs in Windows do not offer this feature. Depending on your distribution, the partition manager may be different from another. However, in this case, we will be using Gparted as our example.

Once the installer has started, some distributions including Ubuntu and Linux Mint, may give you two options and both will be explained below:

Option1 (available only in some distributions)– Install alongside Windows



This option allows you to give the distribution permission to automatically create it's own three partitions:
  1. /boot (which is where Linux will install your boot loader to allowthe choice of booting between OS's)
  2. swap (This is the equivalent of virtual memory in Windows)
  3. /(root) (This is where your file system will be installed and also in this case your personal files too and takes the rest of your partition space)

This is generally acceptable, but the disadvantage of this method is that it works in a way similar to the Windows C: drive on most computers where it is the one partition, meaning that because both your file system and personal files are in the one partition and an issue occurs with the file system requiring a re-install, then you lose the personal files too. The advantage of this is that if the user is not confident enough to manually partition, then this option can save a lot of time and hassle.

Option2 – Something else (or manually partition drives)



This option requires the user to create the partitions manually beside the Windows partition. If this is your first time, then it is recommended that you read and follow through our guide on manual partitioning .

With this manual method we can create the same structure as the automatic method, but add a fourth partition:

Note: All partitions in this guide will be created with. ext4 file systems.
  1. /boot (recommended size around 500mb)
  2. /swap (consistent to the amount of RAM installed in the computer e.g2GB RAM, the swap should be 2048mb)
  3. / (recommended size should be about 10000mb to allow for additional installations of programs and updates)
  4. /home (this is similar to the windows 'my documents' folder where your personal files go and can take the rest of the partition space if needed by the user)

 



The advantage of this method is redundancy. If something were to go wrong with the root file system, then the user can re-install the distribution and not lose any of their personal files as they are on a separate partition.

Whichever way that the user chooses, they will be able to now, once installation is completed, boot into either windows or their Linux distribution through the boot menu.



Dual Booting with Two or More Linux Distributions.

The method for dual booting more than one Linux based distribution is similar to that of the windows-linux method. However, in this guide, it will be a fresh install of both distributions. In this example there are 84GB of hard drive space and it's the user's choice how much they would like to use for each distribution and will be explained in the following steps:

Note: All partitions in this guide will be created with .ext 4 file systems.

Distribution One

Firstly we have to install our first distribution to the hard drive. An option that will allow you to install on full disk space automatically or manually install will appear in some distributions, but in order to dual boot then we have to select manual. The hard drive should have the following partition structure;
  1. sda1- /boot (recommended 500mb and setup as a primary partition)
  2. sda2- swap (consistent to the amount of RAM however in this example 3072mb and primary partition)
  3. sda3- / (recommended around roughly 10000mb)
  4. sda4- Now the /boot and / partitions have been setup as primary partitions we can now set the rest of the space as an extended or logical partition which will be sda4. Then continue creating partitions inside the extended partition. Also remember the following partition (sda5) is not necessary but is recommended and will be used in this tutorial for good practice.
  5. sda5- /home (e.g. 30000mb)

 



This now leaves roughly 39-40GB for the second distribution. Continue the installation process and boot in to it to make sure the installation went through correctly.

Distribution Two

Now that the first distribution is installed we can now start the installer for the second distribution and proceed as before. Again, some distributions may offer the choice to automatically install alongside the other OS. This time it is acceptable to choose this option and let the distribution take the rest of the space, but as with the windows guide you will not have a separate partition for your personal files. If you choose manually then partition as follows:
6. sda6/ (recommended 10000mb)
7. sda7/home (this can now be the remaining space of the hard drive)
Continue with the installation and if asked at any point where to install the boot loader then point it to sda1 which is the boot partition.



Note: The second distribution boot loader will overwrite the one created by the first one but you will still have both entries to choose from.



The same process for distribution two, can be repeated as many times as necessary within the hard drive space limits, with or without the /home partition, if desired.

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