Industrial IoT Security: Designing OTA Updates That Recover From Failure Key Highlights - Industrial Linux devices require specialized OTA update strategies to ensure safety, security and minimal downtime during software upgrades. - A/B system updates, combined with hardware-assisted redundancy, allow seamless updates and automatic recovery from failures without service interruption. - Physical storage options like independent SD cards and SSDs enhance resilience, enabling systems to switch between multiple bootable images safely. - Implementing cryptographically signed update bundles and generating Software Bills of Materials (SBOMs) ensures security, traceability and compliance with regulatory standards. Every engineer who ships an industrial Linux device eventually reaches the same question: how do you update hardware that is installed in a cabinet, on a factory floor or at a remote site without prolonged service interruption, a site visit or risking a bricked device? For a development board on a workbench, updating Linux can be as simple as connecting over SSH and running apt upgrade. Industrial devices are different. They may be difficult to access, connected through unreliable networks or expected to operate continuously for years. A failed update, unexpected power loss or application that fails to start after reboot can turn a routine software release into a service call. A robust over-the-air (OTA) update therefore needs to do more than copy files. It must install a complete system safely, verify that it works and recover automatically if it does not. A practical architecture combines A/B system updates, hardware-assisted rollback, signed update bundles, software bills of materials (SBOMs) and reproducible builds. This article explores those concepts using Strato Pi Max from Sfera Labs and Rugix from Silitics as examples. Together, they provide an effective combination of industrial hardware with multiple physical storage options and a software stack designed for robust, reproducible updates. Why industrial OTA updates are