Installing Arch Linux with LVM and cryptsetup

Rafael Coelho — Mon, 29 Mar 2021 15:54:20 +0000

As a software developer, you probably already know that anyone with a small amount of programming knowledge should be using Arch Linux (that's a joke).

Honestly, I'm writing this post in order to have a quick guide for myself whenever I like to install Arch Linux. I hope you find it useful.

Some disclaimers before we start. First, this tutorial is almost a copy and paste from the original Arch Linux wiki. I think it suits my needs better than the Wiki and I hope you think it does that too. Second, this post is much more like a script than a tutorial which is concerned to explain the meaning and consequences of every single command. For that I think you'll find better answers inside the Arch Linux Wiki.

Downloading

Download the latest version of Arch Linux here.

Create a bootable USB with Rufus if you're using Windows, or with dd

Pre-Installing

1) Load a custom key map. For me, it's the Brazilian standard (ABNT).

loadkeys br-abnt

2) Verify you're connected to the internet

ping dev.to

3) Update system time and date

timedatectl set-ntp true

4) Partition the disk

Verify your current disk state with fdisk -l

In my case, the target disk is mounted at /dev/sda. Make sure to take note of your mount point, otherwise you may format the wrong disk and loose all your data.

Execute fdisk /dev/sdX, where X is the letter of your disk.

You be redirected to another console where you'll be able to format and create partitions on the selected disk.

First, we'll execute g to create a GPT disklabel.

Next, we have to create two partitions: 1) One for your boot files and 2) another one to hold all the OS data.

To create the first partition, we'll type n and press Enter. We'll press enter to next two options (partition number and first sector) in order to select the default values, and finally write +500M in the third option in order to allocate 500Mb of space to it.

To create the second partition, we'll again execute the n command and select the default values (pressing Enter) to all the options since we want all the available space to the second partition.

Finally, by pressing t and selecting 1 for the first partition and 1, which is the code for EFI System, we are able to replace the default partition type of our first partition for the one we need.

To write the modifications press w.

5) Encrypting the partitions

Once we have the partitions set, we can encrypt the one which will hold the OS and all our data.

In my case, it's the /dev/sda2.

cryptsetup luksFormat /dev/sdX

Remember that if you forget your password, you'll loose all the data stored in the partition forever.

cryptsetup open /dev/sda2 cryptlvm

6) Create the LVM

pvcreate /dev/mapper/cryptlvm

vgcreate CryptDisk /dev/mapper/cryptlvm

lvcreate -L 8G CryptDisk -n swap

lvcreate -l 100%FREE CryptDisk -n root

7) Format the partitions

Replace the XX with the letter and number of your boot partition (the 500Mb one)

mkfs.msdos -F32 /dev/sdXX

mkfs.ext4 /dev/CryptDisk/root

mkswap /dev/CryptDisk/swap

8) Mount the partitions

mount /dev/CryptDisk/root /mnt

swapon /dev/CryptDisk/swap

mkdir /mnt/boot

mount /dev/sdXX /mnt/boot # Replace XX with your 500Mb partition

Congratulations, you're ready to install Arch Linux!!!

Installing

If you don't live in US or Europe the mirrors used to download the Arch Linux are not the best for you. Thus, I recommend you to rank the mirrors in order to have the best performance when downloading the OS.

pacman -S pacman-contrib

cp /etc/pacman.d/mirrorlist /etc/pacman.d/mirrorlist.backup

rankmirrors -n 6 /etc/pacman.d/mirrorlist.backup > /etc/pacman.d/mirrorlist

It usually takes around 5 to 10 minutes to run this process.

Finally, it's time to install Arch Linux!!!

pacstrap /mnt base base-devel linux linux-firmware

Configuration

Since we'll have to edit some configuration files, I start by installing vim, but you may use another text editor of your choice.

pacman -Sy vim

1) Generate fstab configuration file.

genfstab -U /mnt >> /mnt/etc/fstab

2) Login into the installed system

arch-chroot /mnt

3) Time Zone

ln -sf /usr/share/zoneinfo/America/Sao_Paulo /etc/localtime

hwclock --systohc

4) Locales

Edit /etc/locale.gen and uncomment en_US.UTF-8 UTF-8 and any other locale that you might need.

vim /etc/locale.gen

locale-gen

echo "LANG=en_US.UTF-8" > /etc/locale.conf

localectl set-keymap --no-convert br-abnt # Replace "br-abnt" with your keyboard type

5) Network

echo "rafael-dell" > /etc/hostname

Modify the /etc/hosts file.

127.0.0.1   localhost
::1     localhost
127.0.1.1   rafael-dell.localdomain rafael-dell

6) initramfs

Since we're using custom configurations (LVM and ecrypted disk), we have to modify the /etc/mkinitcpio.conf so the machine can be properly booted.

vim /etc/mkinitcpio.conf

Add the followings commands in the HOOKS: encrypt lvm2 keyboard

7) Install the bootloader

pacman -S grub

grub-install --target=x86_64-efi --efi-directory=/boot --bootloader-id=GRUB

Since we have an encrypted disk, we need to set a few grub variables before generating the grub configuration files.

Edit the file /etc/default/grub and modify the following lines:

GRUB_CMDLINE_LINUX="cryptdevice=UUID=<device-UUID>:cryptlvm root=/dev/CryptDisk/root rw"
GRUB_ENABLE_CRYPTODISK=y

You'll have to replace the <device-UUID> with the encrypted partition UUID. If you're using vim, you can execute read ! blkid /dev/sdXX to paste the partition's UUID, otherwise you can run lsblk -f and get it.

8) Set up a root password

passwd

And we are done. Now you can reboot and enjoy your

DEV Community: Rafael Coelho

Installing Arch Linux with LVM and cryptsetup

Downloading

Pre-Installing

Installing

Configuration