RAUC uses an A/B partition system to facilitate a safe, foolproof update process. When the system boots off of Partition A, the updates will be applied to the B partition, and vice-versa. This allows the system to fallback onto another partition if one fails, either during operation or during the update process.
Despite the A/B partitions being read-only, Valve allows users to disable the Read-only Filesystem using a simple shell command. However, after an update, the modifications a user has made to the read-only filesystem are lost unless SteamOS is configured to use a folder in writeable storage to overlay the read-only storage.
- Fail-Safe & Atomic
- An update may be interrupted at any point without breaking the running system.
- Update compatibility check
- Atomic bootloader updates (eMMC boot partitions, MBR, GPT)
- Cryptographic signing and verification of updates using OpenSSL (signatures based on x.509 certificates)
- Symmetric setup (Root-FS A & B)
- Asymmetric setup (recovery & normal)
- Application partition, data partitions, ...
- Allows grouping of multiple slots (rootfs, appfs) as update targets
- Built-in network streaming mode
- Network delta-streaming mode (using casync)
- Chunk-based binary delta updates
- Significantly reduce download size
- No extra storage required
- Bundle encryption for multiple recipients
- Independent from update source
- USB Stick
- Software provisioning server (e.g. hawkBit)
- Supports data migration
- Network protocol support using libcurl (https, http, ftp, ssh, ...)
- Several layers of update customization
- Update-specific extensions (hooks)
- System-specific extensions (handlers)
- Fully custom update script
- "Portable Linux gaming with the Steam Deck". Collabora. Retrieved 2022-08-12.
- "RAUC - Safe and secure software updates for embedded Linux". github.com. Retrieved 2022-08-12.