Follow the guid completely and carefully for optimal results.

To format your drive as ZFS first run lsblk and remember the name of the drive that you want to format as ZFS!

In my case It's: /dev/sda

cDucky@snow:~/ > lsblk
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
sda      8:0    0 476.9G  0 disk
├─sda1   8:1    0   800M  0 part /boot
└─sda2   8:2    0 476.2G  0 part

(Note: Replace <your drive name> with the name of the drive that you want to install NixOS on.)

To partition the drive using gdisk run these commands:

sudo su
gdisk /dev/<your drive name>
Type o then press enter
And then answer y then press enter
And type q then enter to quit gdisk

cgdisk /dev/<your drive name>
Now delete all partitions
Create a new partition
Use default on the first sector (Press enter without any text)
For size in sectors or {KMGPT} part type +800M and press enter
For hex code or GUID type ef00 and press enter
As of the name use: NIXBOOT

Create a new partition in the bigger unallocated space
Use default when prompted on all options (Press enter without any text)
As of the name use: NIXROOT

Write and Quit

Now lets make a fat32 file system for the NIXBOOT partition

sudo mkfs.vfat -F 32 /dev/<your drive name>

Now lets name the NIXBOOT partition

sudo fatlabel /dev/<your drive name> NIXBOOT

Create a zpool and encrypt the drive

sudo zpool create -f \
-o altroot="/mnt" \
-o ashift=12 \
-o autotrim=on \
-O compression=lz4 \
-O acltype=posixacl \
-O xattr=sa \
-O relatime=on \
-O normalization=formD \
-O dnodesize=auto \
-O sync=disabled \
-O encryption=aes-256-gcm \
-O keylocation=prompt \
-O keyformat=passphrase \
-O mountpoint=none \
NIXROOT \
/dev/<your drive name>

enter your prefered password and DON'T forget it!
(Note: You can't see the password that you enter to the terminal don't worry!)

Create ZFS partitions with these commands

sudo zfs create -o mountpoint=legacy NIXROOT/root
sudo zfs create -o mountpoint=legacy NIXROOT/home
sudo zfs create -o refreservation=1G -o mountpoint=none NIXROOT/reserved

Mounting the partitions

sudo mount -t zfs NIXROOT/root /mnt
sudo mkdir /mnt/boot
sudo mkdir /mnt/home
sudo mount /dev/<your drive name> /mnt/boot
sudo mount -t zfs NIXROOT/home /mnt/home

sudo nixos-generate-config --root /mnt

Thanks to @mcdonc for the ZFS part!

open the /mnt/etc/nixos/configuration.nix file with your preferred editor.

sudo nano /mnt/etc/nixos/configuration.nix
or
sudo vim /mnt/etc/nixos/configuration.nix

• Remove everything from your config and copy and paste my hole config linked here

• Run head -c 8 /etc/machine-id and replace <your host id> in line 14 with the number from the command's output.

• Replace <your preferred host name> in line 26 with the name that you want to set for your computer. (You can choose anything!)

• In line 35 replace <Continent/Country or City> with your time zone.

• At line 53 you can choose which Desktop Environment or Window Manager you want. By default I have set i3 and icewm but you can remove them or add other Desktop Environments or Window Managers! To add a Desktop Environment or Window Manager go to search.nixos.org/options and search your preferred Desktop Environment or Window Manager then copy and paste the one with .enable at the end. After pasting add = true; at the end. An example for the KDE Desktop Environment:

services.xserver.desktopManager.plasma5.enable = true;

• To enable other shells go to line 59 and uncomment the shell you would like, Then to set the default shell uncomment line 91 and replace <your preferred shell> with the name of the shell that you uncommented at line 59. Here is an example:

users.defaultUserShell = pkgs.zsh;

(Note: Uncommenting means removing the # that is before the line!)

• For adding fonts go to line 64 and add your preferred fonts there. I've added some fonts that are usually used in some config files you can delete them if you want to but you probably need them later! You can find other fonts by searching the name of your font at search.nixos.org/packages.

• Also don't forget to change your user name at line 92! You can just do that by replacing <your user name> with the user name that you want.

• I've included some essential programs you might need! At line 103 you can remove them or add some other programs to them. To search the program you might want go to search.nixos.org/packages and search them there!

• Depending to the time that you are reading this you might need to change the system state version, To do it go to line 181 and change the number to the version of the iso that you have.

• Save and exit when you are done editing your configuration.nix file.

If you need other modules consider checking out nixos.org/manual/nixos/stable!

• After you are done configuring your configuration file run:

sudo nixos-install

• After downloading the apps/DE/WM/... that you chose its going to ask you for the root password. Set a strong and complicated password! (Note: The password that you are typing wont show up in the terminal don't worry!)

• Now reboot!

• While booting you shoud enter your ZFS encryption password!

• After booting go to a tty by pressing ctrl+alt+f1 (Sometimes fn too!) and login as root, Then run:

passwd <your user name>

And type in the password that you want for your normal user.

Run: exit and go to tty 7 by pressing ctrl+alt+f7 (Sometimes fn too!) and login with the password that you just set!

• After you loged in go to a terminal and run:

sudo nmtui

to connect to a wireless network!

• If this heleped you please consider giving it a ⭐️. Thanks!