An installation environment, also known as a live ISO is exactly what the name suggests - an environment for installing a linux distribution, in this case - Gentoo.

Most linux distributions ship their own installation environment (LiveISO) and Gentoo is no different, however I'd advise against using the one, provided by Gentoo. It makes the installation process unnecessarily difficult by not having a desktop environment.

Gentoo can be installed using any other linux distribution's installation environment, most of which have a nice pre-configured desktop that makes the whole installation process a lot less annoying by allowing you to copy-paste long commands and to do something else while waiting for it to finish.

For this guide, I'll be using a Linux Mint live ISO, however as mentioned previously, pretty much any other distribution's live ISO should also get the job done.

Before beginning, you are gonna need a few things:

I'm gonna assume that anyone who's gotten to this point already knows how to flash an ISO to a flash drive and boot from it, however I am still gonna mention Ventoy, because it's cool.

Now that you've booted off your chosen distro's live ISO, it's time to actually install Gentoo, starting with:

Before doing any partitioning, you firstly need to choose a disk to be partitioned. There are no strict restrictions about what disk should be used, however it is generally recommended to install any operating system on an SSD, instead of an HDD.

To check the names of all disks, currently connected to your system, use:

SATA disks should appear as /dev/sd*, NVME disks should appear as /dev/nvme*n*.

There is a slight catch that needs to be taken care of, before proceeding with partitioning the disk. That being whether your system is Legacy BIOS or UEFI, as the following steps differ slightly for each one. If you are unsure about your system, you can type the following command:

If the command errors out, your system is legacy BIOS and if it doesn't, it's UEFI.

For the following steps, you can use whichever disk management program you want (e.g. gparted, GNOME disks, etc), cfdisk will be used for the demonstration.

1st, wipe the existing partition table on the chosen disk:

After that, depending on whether your computer is legacy BIOS or UEFI, you're gonna have to set the disks up a little bit differently:

Set the partition table to GPT
Create 3 partitions:

Set the partition table to MBR/DOS
Create 2 partitions:

Set the partition you created for using as root to bootable

But what about swap?

Don't worry about it, we'll get there when we get there. (Check the setting up zram swap chapter for more info on that)

Alright, now that you've made your partitions, it's time to format them appropriately.

You have a choice to make with the file system you want to use, as each one has it's own unique advantages. Here are some of the more common file systems:

Now that you've chosen your file system, it's time to format your partitions with it. In the example case:

At this point, your disk's partition table should looks something like this:

Everything looks good? Now it's time to:

Before going any further, you might wonder, what's a 'stage 3' ?

A 'stage 3' is simply an archived, basic gentoo system, which needs to be extracted on a disk partition in order for anything useful to be done with it.

Before any of that can be done, however, you need to mount your newly created partitions first. Here's how that's done:

1st, create a root mount point:

2nd, mount the root partition:

3rd, create the other mount points:

4th, mount the other partitions:

- Wait, aren't these 'mount points' just directories?

Yes! On linux, disk partitions are mounted as directories.

With all of that done, you are now ready to download the gentoo stage3

1st, go to the Gentoo downloads page, then select which version of the gentoo base system you want. If the words 'systemd' and 'openrc' mean nothing to you or you can't choose between the two init systems, choose the 'openrc' option