Arch Linux Docker install with BTRFS

arch-docker.sh

# Install Docker first
pacman -S docker

# Create subvolume for Docker images
cd /mnt/t20root
btrfs subvolume create svols/docker
# Create subvolume 'svols/docker'

btrfs subvolume list .
# ID 256 gen 1349 top level 5 path svols/root
# ID 257 gen 1337 top level 5 path svols/home
# ID 263 gen 1350 top level 5 path svols/docker

# Edit /etc/fstab
nano /etc/fstab
# # /dev/sda2 UUID=381dc812-9bde-4a4e-8af1-cd6546ffec6e
# LABEL=t20sda2           /var/lib/docker btrfs           rw,noatime,nodiratime,compress=zstd:3,space_cache=v2,subvol=/svols/docker               0 0

reboot

# Check if mount directory exists and if subvolume is mounted
ls -la /mnt/t20root/svols/root/var/lib
# drwxr-xr-x 1 root root   0 May 22 17:32 docker

mount -v
# /dev/sda2 on /var/lib/docker type btrfs (rw,noatime,nodiratime,compress=zstd:3,space_cache=v2,subvolid=263,subvol=/svols/docker)

# Finally start and enable docker - https://wiki.archlinux.org/title/Systemd#Using_units
systemctl start docker
systemctl enable docker
# Created symlink /etc/systemd/system/multi-user.target.wants/docker.service → /usr/lib/systemd/system/docker.service.

# Testing it
docker run -it --rm archlinux bash -c "echo hello world"
# Unable to find image 'archlinux:latest' locally
# latest: Pulling from library/archlinux
# 6b2c4032adc9: Pull complete
# e511435eb07f: Pull complete
# Digest: sha256:ebe6578e11149ab4ab294bc0d1c0907d5a1c77a39707802179fdb6519a81d6e2
# Status: Downloaded newer image for archlinux:latest
# hello world

# list subvolumens from /
btrfs subvolume list /
# ID 256 gen 1398 top level 5 path svols/root
# ID 257 gen 1391 top level 5 path svols/home
# ID 263 gen 1388 top level 5 path svols/docker
# ID 264 gen 1385 top level 263 path svols/docker/btrfs/subvolumes/f864609c071e1a5d559a77aec83a1f8d72e95c37475c1f10f36e5a488d3075e8
# ID 265 gen 1386 top level 263 path svols/docker/btrfs/subvolumes/67e302d7c5852f57fb2073b0ab06be5a3909f3137f9c0a1ace8326f37ee6cfb1

# list subvolumens from svols/docker
btrfs subvolume list /mnt/t20root/svols/docker
# ID 256 gen 1398 top level 5 path svols/root
# ID 257 gen 1391 top level 5 path svols/home
# ID 263 gen 1388 top level 5 path svols/docker
# ID 264 gen 1385 top level 263 path btrfs/subvolumes/f864609c071e1a5d559a77aec83a1f8d72e95c37475c1f10f36e5a488d3075e8
# ID 265 gen 1386 top level 263 path btrfs/subvolumes/67e302d7c5852f57fb2073b0ab06be5a3909f3137f9c0a1ace8326f37ee6cfb1

# some more "ambitious" test
docker run -d -p 80:80 docker/getting-started

docker ps
# CONTAINER ID   IMAGE                    COMMAND                  CREATED         STATUS         PORTS                               NAMES
# 7672d0dca7fd   docker/getting-started   "/docker-entrypoint.…"   7 seconds ago   Up 5 seconds   0.0.0.0:80->80/tcp, :::80->80/tcp   jovial_lichterman

# Try access server on port 80 to check if container is running properly