Reliable under real‑world conditions
YAFFS is engineered to cope with power cuts, bad blocks and long‑term wear, so your products remain dependable over years, not days.
Reliable flash file system since 2002
Reliable, consistent flash storage for embedded systems
YAFFS (Yet Another Flash File System) is purpose‑built for raw NAND and NOR flash, keeping your data safe and behaviour predictable even under power loss, resets and harsh conditions.
What
What is YAFFS?
YAFFS is an open‑source flash file system, designed from the ground up for raw NAND and NOR flash in embedded systems. It provides robust journalling, predictable behaviour and minimal overhead, without relying on a separate flash translation layer.
- Purpose‑built for raw flash, not adapted from spinning disks.
- Resilient to power loss and unexpected resets.
- Consistent, predictable behaviour over long‑term use.
- Suitable for Linux, RTOS or bare‑metal deployments.
Who
Who is YAFFS for?
YAFFS is for teams who care deeply about the reliability and consistency of their flash storage.
- Embedded / firmware engineers building products on raw NAND or NOR flash.
- Technical leads responsible for robustness in industrial, networking and infrastructure systems.
- Aerospace, avionics and other applications where failure is simply not an option.
If you need flash storage that is boringly predictable in production, YAFFS is built for you.
Why
Why teams choose YAFFS
Reliability and consistency are YAFFS’ core strengths. Other benefits come along for the ride.
Predictable, consistent behaviour
The file system is designed for stable, repeatable behaviour – helping you avoid “works in the lab, fails in the field” surprises.
Proven in demanding deployments
YAFFS has shipped in high‑volume commercial products and critical systems since 2002, including spacecraft missions.
YAFFS in space – NASA TESS
NASA’s Transiting Exoplanet Survey Satellite (TESS) uses YAFFS to store incoming data from its instruments before transmission back to Earth. TESS has been operating successfully in space for years, continuously gathering science data.
Not every file system is robust enough for this kind of work. YAFFS’ reliability and consistent behaviour under stress were key reasons for its selection.
Trusted by
Used in real products
YAFFS is in long‑lived products from companies across networking, industrial control, sewing and more.
Industrial control systems
Networking & security appliances
Consumer devices
Avionics & space
Need help deciding if YAFFS fits?
If you are choosing between YAFFS and other flash file systems, we can help you think through the trade‑offs and the realities of your specific hardware and workload.
Start with a quick read of our design notes, then talk to the engineers who build and maintain YAFFS.
Explore docs & resourcesConsulting from the YAFFS team
For more than 20 years the YAFFS architects have been helping teams make flash storage behave – from architecture reviews to deep debugging of corruption and performance issues.
We have probably seen a problem very similar to yours before.
Learn about consulting