What Is an Immutable Linux Distro? (And Should You Use One?)

Immutable Linux distributions ship the entire OS as a single versioned, read-only image instead of individual packages. This design improves stability, resists tampering, and enables reliable rollbacks — without removing the ability to customize. User data, configs, and applications persist normally; only the base OS layer is locked. Different distros implement immutability differently: Fedora Atomic uses OSTree, openSUSE MicroOS uses transactional updates with Btrfs snapshots, and Ubuntu Core uses an A/B partition model. Applications are typically managed via Flatpak or package layering outside the base OS. While immutable distros are still maturing and not yet the default for most use cases, they are gaining real-world adoption (e.g., SteamOS on Steam Deck) and represent a meaningful architectural shift in how Linux systems are managed.