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Partition the Drive

Jan 15, 2024, 2 min read

Check for UEFI

Before doing this, make sure your system uses EFI. You can check by finding the efivars folder.

[[ -d /sys/firmware/efi/efivars ]] && echo "EFI" || echo "BIOS"

If it returns BIOS, don’t use this guide.

Find the Right Drive

Sometimes /dev/sda is not the drive you want to install to. On virtual machines it can be /dev/vda, and on newer systems it can be /dev/nvme0n1. To make sure you use the right drive, check with lsblk.

Partitioning

Now we will make the actual partitions. If you are uncomfortable with using parted, you can use cfdisk in the same way.

Create a new GPT partition table (this will wipe your drive).

parted /dev/sda -- mklabel gpt

Add the root partition. This will fill the whole disk, besides the 512MB in front (for the boot partition).

parted /dev/sda -- mkpart primary 512MB 100%

Finally, the boot partition. It uses the reserved 512MB at the start of the disk.

parted /dev/sda -- mkpart ESP fat32 1MB 512MB

Formatting

For creating boot partitions (fat32), use mkfs.fat. Assign a label to the boot partition with -n.

mkfs.fat -F 32 -n boot /dev/sda3

For creating btrfs partitions, use mkfs.btrfs. -L labels the partition.

mkfs.btrfs -L root /dev/sda1

Subvolumes

For this install, we’ll have the following subvolumes:

  • @ – This is the main root subvolume /.
  • @tmp – Contains certain temporory files and caches
  • @var - More temporary files
  • @home - This is the home directory. This consists of most of your data including Desktop and Downloads. (Note: Not necessary with systemd-homed)
  • @snapshots – Directory to store snapshots.
mount --mkdir /dev/disk/by-label/root /mnt/btrfs
cd /mnt/btrfs
btrfs subvolume create @
btrfs subvolume create @var
btrfs subvolume create @tmp
btrfs subvolume create @home # Optional
btrfs subvolume create @snapshots

Mounting

We’ll mount all of the subvolumes:

mount -o subvol=@ /dev/disk/by-label/root /mnt
 
mount --mkdir -o subvol=@var /dev/disk/by-label/root /mnt/var
mount --mkdir -o subvol=@tmp /dev/disk/by-label/root /mnt/tmp
mount --mkdir -o subvol=@home /dev/disk/by-label/root /mnt/home # If you created it
mount --mkdir -o subvol=@snapshots /dev/disk/by-label/root /mnt/.snapshots

Mount the EFI Boot partition to /mnt/efi.

mount --mkdir /dev/disk/by-label/boot /mnt/efi

Swapfile

You’ll notice that we didn’t allocate any space for a swap partition. That’s because we’re using a swap file.

btrfs subvolume create @swap
mount --mkdir -o subvol=@swap /dev/disk/by-label/root /mnt/swap
btrfs filesystem mkswapfile --size 4g --uuid clear /mnt/swap/swapfile

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