Btrfs before install notes

Set up BTRFS before install, according to this guide

(You are booted in the Arch Live environment meant to install Arch on your machine or VM)

Contents 1 Before pacstrap (01:50) 1.1 Partitionning (02:05) 1.2 Formatting (02:50) 1.3 Start mounting and playing with BTRFS (04:50) 2 It's pactsrap time now (07:00) 2.1 And now... 3 then reboot

Before pacstrap (01:50)

loadkeys for your keyboard

Select device with fdisk -l ; VM devices starts with V here, as in /dev/vda1 et

Partitionning (02:05)

fdisk /dev/vda

• Use g to create a GPT partition table on /dev/vda1

• Use n to create a first EFI partition

• Use +300M to make it 300M in size

• Use t to change its type to 1 to make it an EFI partition

• Use n to create a second partition for the rest of the disk

• Use p to check for values and mistakes

• Use w to write the modifications and exit the interactive fdisk prompt

Formatting (02:50)

• mkfs.fat -F 32 /dev/vda1
• mkfs.btrfs /dev/vda2

Start mounting and playing with BTRFS (04:50)

• mount /dev/vda2 /mnt

• create subvolumes with

btrfs subvolume create /mnt/@
btrfs subvolume create /mnt/@home
btrfs subvolume create /mnt/@snapshots

• Check your existing subvolumes and their ID :

btrfs subvolume list /

(Reminder : subvolumes don't create snapshots of nested subvolumes ; here @ won't contain @home or @snapshots data)

• Create mountpoints

mkdir /mnt/efi
mkdir /mnt/home
mkdir /mnt/.snapshots
mkdir /mnt/btrfsroot

• Then Umount the actual /dev/vda2 to replace by the @ subvolume

mount /dev/vda2 -o subvolid=256 /mnt
mount /dev/vda2 -o subvolid=257 /mnt/home
mount /dev/vda2 -o subvolid=258 /mnt/.snapshots
mount /dev/vda2 -o subvolid=5 /mnt/btrfsroot
mount /dev/vda1 /mnt/efi

It's pactsrap time now (07:00)

pacstrap -K /mnt base linux base-devel grub sudo git less nano efibootmgr btrfs-progs snapper snap-pac grub-btrfs tar sudo

Sodding network here man...

And now...

* check your mount points list for any misstep with mount

create your fstab file when mount is all ok

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

Check again with less /mnt/etc/fstab

arch-chroot /mnt if everything is good

• you still have to do the usual : vconsole.conf for the keymap, locale-gen for lang etc, see the arch install guide

• Do the mkinit just in case :

mkinitcpio -P

• Install GRUB with this :

add --removable to the grub install line if necessary

then do grub-mkconfig

then reboot

--failed at grub / creating bootable system phase--