Reliability and Guaranteed Consistency for Your Flash File System

YAFFS delivers proven robustness where failure is not an option—from NASA satellites to critical infrastructure. Power-fail tested through hundreds of millions of cycles.

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Running in NASA's TESS Satellite for 7+ Years in Space

Why YAFFS?

When data integrity and system reliability are non-negotiable

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Guaranteed Consistency

Power-fail resilient design ensures your data remains consistent even during unexpected shutdowns. Tested through hundreds of millions of power-fail cycles to prove reliability where others claim it.

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Built for Flash Memory

Log-structured architecture designed specifically for NAND and NOR flash characteristics—not a hard disk file system adapted for flash. Automatic wear leveling, no translation layer overhead.

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Battle-Tested Since 2002

Proven in millions of devices from consumer electronics to aerospace applications. Used by NASA, infrastructure providers, medical device manufacturers, and high-volume consumer products.

🛰️ YAFFS in Space

Trusted by NASA for the TESS Mission

The NASA Transiting Exoplanet Survey Satellite (TESS) has relied on YAFFS since its launch in April 2018—over 7 years in the harsh environment of space.

TESS uses YAFFS to store incoming exoplanet data and preserve it reliably before transmission to Earth. The satellite has discovered over 500 confirmed planets and 7,000+ candidates.

Some file systems aren't robust enough for space. YAFFS has proven itself where failure means mission failure.

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Who Needs YAFFS?

Critical systems where data integrity and reliability are paramount

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Aerospace & Defense

Satellite systems, avionics, mission-critical defense applications where failure is not acceptable and maintenance is impossible.

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Critical Infrastructure

Power grids, telecommunications equipment, industrial control systems requiring guaranteed data consistency and decades of operation.

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Medical Devices

Devices requiring regulatory compliance, data integrity for patient safety, and absolute reliability in life-critical applications.

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High-Volume Consumer

Products deployed in millions of units where reliability at scale matters. Used in Android devices, cameras, point-of-sale systems.

Trusted by Industry Leaders

YAFFS is used in millions of devices worldwide

NASA

Android

Eaton

Leica

LANCOM

Bernina

Gallagher

Why Choose YAFFS Over Alternatives?

Feature	YAFFS	Alternatives (JFFS2, F2FS, FTL-based)
Power-Fail Resilience	✅ Designed from day one, tested through 100M+ cycles	⚠️ Varies; often bolted on, less thoroughly tested
Boot Speed	✅ Fast checkpoint-based boot, single-pass scanning	⚠️ Often slower, multiple passes required
RAM Footprint	✅ Optimized for embedded systems	⚠️ Can be higher, especially on large filesystems
Flash-Specific Design	✅ Log-structured, no FTL needed, automatic wear leveling	⚠️ Often adapted from disk FS or requires FTL layer
Proven Track Record	✅ 20+ years, millions of devices, space missions	⚠️ Varies; newer systems lack long-term field data
Expert Support Available	✅ Original architects available for consulting	⚠️ Community-only or vendor-dependent

See Detailed Technical Comparison

Key Technical Features

Engineering excellence in every detail

Log-Structured Design

Faster writes, inherent wear leveling, and superior robustness compared to traditional block-structured file systems.

Power-Fail Recovery

Designed so power loss is a normal event. Checkpoint system and robust scanning ensure consistency without lengthy recovery.

Bad Block Handling

Automatic detection and management of bad blocks without over-provisioning requirements.

Flash Error Correction

Works with hardware or software ECC, handles read/write disturbs through block refreshing.

Efficient Garbage Collection

Background reclamation minimizes write amplification and keeps clean blocks ready for fast writes.

Portable & Flexible

Works with Linux, VxWorks, eCos, Windows CE, or bare metal. Supports NAND (SLC/MLC/TLC) and NOR flash.

Get Started with YAFFS

Download YAFFS

Get the GPL version from our repository. Open source with full access to the code that's proven in space.

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Need Expert Help?

20+ years solving flash file system challenges. Architecture review, integration, troubleshooting—we've probably seen it before.

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Explore Documentation

Comprehensive technical documentation, integration guides, specifications, and testing methodology.

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