When power fails unexpectedly, YAFFS keeps your data safe. Purpose-built for NAND and NOR flash, trusted by NASA, running in millions of devices since 2002.
YAFFS (Yet Another Flash File System) is a file system designed specifically for flash memory. Unlike general-purpose file systems adapted from hard drives, YAFFS understands how flash works.
It handles the challenges of flash storage automatically: bad block management, wear levelling, and most importantly, guaranteed data consistency even when power fails without warning.
Available under GPL for open-source projects, or with commercial licensing for proprietary products. Full source code, no royalties, no ongoing fees.
Running on NASA's TESS satellite since 2018
The Transiting Exoplanet Survey Satellite has been using YAFFS in space for over 7 years—where a file system failure would mean mission failure, and there's no way to reboot.
In embedded systems, reliability isn't optional. YAFFS is engineered from the ground up to keep your data safe, no matter what.
Every write operation is atomic. If power cuts mid-write, YAFFS recovers automatically to a consistent state. No corruption, no lost data, no manual intervention needed.
Log-structured design means your file system is always valid. No lengthy fsck on boot, no orphaned files, no half-written data. The file system is always recoverable.
Flash memory develops bad blocks over time. YAFFS detects and manages them automatically, keeping your system running even as the underlying hardware degrades.
Flash cells have limited write cycles. YAFFS distributes writes evenly across the device, maximising the lifespan of your flash storage.
Works with hardware or software error correction to detect and fix bit errors before they become data corruption. Defence in depth for your data.
Rigorous power-fail testing, stress testing, and real-world validation across millions of devices. When we say it's reliable, we have the data to prove it.
Set-top boxes, cameras, smart home devices, and anywhere reliability matters to end users. Power can be cut at any moment—YAFFS handles it.
Factory automation, PLCs, monitoring systems. When downtime costs money and data loss is unacceptable, YAFFS delivers the reliability you need.
Infotainment systems, dashcams, telematics. Vehicles experience harsh electrical environments—YAFFS keeps data safe through it all.
Diagnostic equipment, portable monitors, implantables. When patient data and device function are critical, YAFFS provides the foundation.
From NASA satellites to military systems. When failure isn't an option and you can't send someone to fix it, YAFFS is the trusted choice.
Routers, switches, access points. Infrastructure that must survive power events and keep configurations intact.
Many file systems were designed for spinning disks and later adapted for flash. YAFFS was built from scratch specifically for NAND flash characteristics, giving it fundamental advantages.
YAFFS is highly portable and runs on virtually any platform. Use it with your existing OS and toolchain.
Choose the licence that fits your project. Both options give you full source code access.
Perfect for open-source projects and evaluation
For proprietary and closed-source products
We've spent over 20 years solving flash storage problems. Whether you're using YAFFS or troubleshooting another file system, we've probably seen your problem before.
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