# Arch Linux Installation

*LVM on LUKS Arch installation with systemd-boot*

## USB

Download Arch Linux

Find out the name of your USB drive with lsblk. Make sure that it is not mounted.

To mount the Arch ISO run the following command, replacing /dev/sdx with your drive, e.g. /dev/sdb. (do not append a partition number, so do not use something like /dev/sdb1):

```shell
dd bs=4M if=/path/to/archlinux.iso of=/dev/sdx status=progress && sync
```

## Preparation

Boot from USB disk

Change default font:

```shell
setfont sun12x22
```

Check if running in UEFI mode:

```shell
ls /sys/firmware/efi
```

If there is any content in this folder then you are in UEFI mode.

Check that there is a connection:

```shell
ping archlinux.org
```

Update the system clock:

```shell
timedatectl set-ntp true
```

Lastly to  enable mirrors, edit `/etc/pacman.d/mirrorlist` and locate your geographic region. Uncomment mirrors you would like to use.

### Partitioning

Get the name of the disk to format/partition:

```shell
lsblk
```

The name should be something like `/dev/sda`

First shred the disk using the shred tool:


```shell
shred -v -n1 /dev/sdX
```

Now partition the disk using `gdisk`:

```shell
gdisk /dev/sda
```

Partition 1 should be an EFI boot partition (code: ef00) of 512MB. Partition 2 should be a Linux LVM partition (8e00). The 2nd partition can take up the full disk or only a part of it. Remember to write the partition table changes to the disk on configuration completion.

Once partitioned you can format the boot partition (the LVM partition needs to be encrypted before it gets formatted)

```shell
mkfs.fat -F32 /dev/sda1
```

### Encryption

First modprobe for `dm-crypt`

```shell
modprobe dm-crypt
```

Now, encrypt the disk:

```shell
cryptsetup luksFormat /dev/sda2
```

Open the disk with the password set above:

```shell
cryptsetup open --type luks /dev/sda2 lvm
```

Check the lvm disk exists:

```shell
ls /dev/mapper/lvm
```

Create a physical volume:

```shell
pvcreate /dev/mapper/lvm
```

Create a volume group:

```shell
vgcreate volume /dev/mapper/lvm
```

Create logical partitions:

```shell
lvcreate -L20G volume -n swap
lvcreate -L40G volume -n root
lvcreate -l 100%FREE volume -n home
```

Format file system on logical partitions:

```shell
mkfs.ext4 /dev/mapper/volume-root
mkfs.ext4 /dev/mapper/volume-home
mkswap /dev/mapper/volume-swap
```

Mount the volumes and file systems:

```shell
mount /dev/mapper/volume-root /mnt
mkdir /mnt/home
mount /mnt/boot
mount /dev/mapper/volume-home /mnt/home
mount /dev/sda1 /mnt/boot
swapon /dev/mapper/volume-swap
```

## Installation

Bootstrap base system onto disk using pacstrap:

```shell
pacstrap /mnt base base-devel vim
```

Generate `fstab`:

```shell
genfstab -p /mnt >> /mnt/etc/fstab
```

`chroot` into system:

```shell
arch-chroot /mnt
```

Set time locale:

```shell
ln -sf /usr/share/zoneinfo/Africa/Johannesburg /etc/localtime
```

Set clock:

```shell
hwclock --systohc
```

Uncomment `en_US.UTF-8 UTF-8` `en_US ISO-8859-1` and other needed localizations in `/etc/locale.gen`. Now run:

```shell
locale-gen
```

Create locale config file:

```shell
locale > /etc/locale.conf
```

Add an hostname:

```shell
vim /etc/hostname
```

Update `/etc/hosts` to contain::

```text
127.0.1.1   myhostname.localdomain  myhostname
```

Because we are using disk encryption we have to change the initramfs.

Edit the `/etc/mkinitcpio.conf`. Look for the HOOKS variable and move `keyboard` to before the `filesystems` and add `encrypt` and `lvm2` after `keyboard`. Like:

```text
HOOKS="base udev autodetect modconf block keyboard encrypt lvm2 filesystems fsck"
```

Regenerate the initramfs:

```shell
mkinitcpio -p linux
```

Install a bootloader:

```shell
bootctl --path=/boot/ install
```

Create bootloader. Edit `/boot/loader/loader.conf`. Replace the file's contents with:

```text
default arch
timeout 3
editor 0
```

The `editor 0` ensures the configuration can't be changed on boot.

Next create a bootloader entry in `/boot/loader/entries/arch.conf`

```text
title Arch Linux
linux /vmlinuz-linux
initrd /initramfs-linux.img
options cryptdevice=UUID={UUID}:volume root=/dev/mapper/volume-root quiet rw
```

In order to get the UUID run the following command in vim:

```shell
:read ! blkid /dev/sda2
```

## Complete

exit `chroot`:

```shell
exit
```

unmount everything:

```shell
umount -R /mnt
```

and reboot

```shell
reboot
```