Lightwhale is an immutable, live-boot ISO that drops you directly into a running Docker Engine with no installation, using overlayfs to layer persistence on top of a read-only squashfs root.
Key Takeaways
Zero-install Docker host: download the ISO, dd it to USB, boot, and Docker is ready; default user is op/opsecret.
Immutable squashfs root: the kernel and rootfs are read-only at all times; only /etc, /var, and /home are writable via overlayfs upper layers.
Magic-header persistence: write the string lightwhale-please-format-me to a block device and Lightwhale auto-partitions, formats with Btrfs, and mounts it as the data filesystem on next boot.
Multi-disk RAID1 support: multiple persistence-enabled devices are automatically assembled into a btrfs --data raid1 volume with no manual configuration.
Docker data lives at /mnt/lightwhale-data/lightwhale-state/docker, fully segregated from the immutable root, making backup and migration a single directory copy.
