2026-09-30 –, Galerie
Managing traditional Linux deployments at scale is a growing bottleneck. This talk dives into the Elemental project and its declarative, distro-agnostic approach to building and managing image-based Linux systems. We will explore the core architectural boundaries Elemental relies on, detailing its assumed OS stack (including the bootloader, systemd, dracut, and snapshotter) and its resilient system layout. Furthermore, we will demonstrate how treating the OS as a declarative entity, managed seamlessly alongside Kubernetes workloads, drastically streamlines image creation, installation, and atomic upgrades.
The shift toward image-based, immutable operating systems is transforming how we manage infrastructure, bringing cloud-native paradigms directly to the OS level. However, adopting this model introduces new challenges around system layout, lifecycle management, and extensibility. This session provides a dive into how the Elemental project tackles these challenges through a distro-agnostic, declarative architecture.
First, we will look under the hood at the architectural boundaries required to make immutability work in practice. We will detail the OS stack Elemental assumes, exploring how components like the bootloader, systemd, dracut, and snapper interact to manage system states. This includes designing a resilient system layout utilizing an immutable, read-only root volume paired with writable shared volumes and safely snapshotted areas for persistent data. We will also address a common challenge: extending the system without compromising its read-only nature. To solve this, we will explore methods like dropping data into persistent areas, utilizing overlays such as systemd-sysext, and deploying sandboxed applications with technologies like portable-services and Podman Quadlets.
The second part of the session focuses on the operational lifecycle and Elemental's opinionated approach to OS management. We will explore how to define image creation, installation, and extensions using a unified, declarative model that pairs seamlessly with Kubernetes. Finally, we will cover the mechanics of state reconciliation—transitioning a system from its current state to a newly defined state, complete with support for fail-safe upgrades.
Starting his career at a research foundation, David Cassany contributed to projects focused on multimedia streaming within open-source Linux ecosystems. For the past decade, he has brought that expertise to SUSE as an open-source software engineer, specializing in Linux appliance build tools, containerized systems, and Kubernetes architectures.
