🧬 FastaFS

FastaFS lets you mount compressed FASTA archives as a virtual filesystem — enabling instant random access without preprocessing, indexing, or duplication.

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❓ Why FastaFS?

Working with large FASTA files is inefficient and error-prone:

• Requires auxiliary files (.fai, .dict)
• Random access needs preprocessing or indexing
• Tools expect flat files, not compressed archives
• Storage is duplicated across pipelines
• Data and metadata can get out of sync

FastaFS solves this by turning compressed FASTA archives into a mountable filesystem.

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🔥 Key Features

• ⚡ Near-native performance – optimized C++ backend with minimal overhead
• 🧠 No on-demand preprocessing required – skip indexing and loading into memory
• 📂 Works with existing tools – use grep, awk, samtools, etc.
• 💾 Efficient storage – no duplicate FASTA files or temporary extraction
• 🔌 Mount as a filesystem – interact like regular files
• 🔄 Preserves compatibility – fully compatible with existing FASTA-based workflows and tooling
• 🎯 Selective decompression – only access the regions you need

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🚀 Quick Start

# Clone
git clone https://github.com/yhoogstrate/fastafs.git
cd fastafs

# Build
./build-release.sh
make check

# Cache + mount
./fastafs cache reference ./reference.fa
./fastafs mount reference /mnt/genome

# Use like normal files
ls /mnt/genome
head /mnt/genome/chr1.fa

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🧠 How it works

FastaFS introduces a virtual filesystem layer using FUSE.

When mounted:

• FASTA and metadata files are generated on-the-fly
• Only requested regions are decompressed
• .fa, .fai, .dict, and .2bit stay perfectly in sync

➡️ No temporary files. No duplication. No indexing overhead.

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🧪 Use Cases

• Large-scale genomics pipelines
• HPC environments with limited I/O bandwidth
• Streaming access to reference genomes
• Toolchains requiring standard FASTA input
• Reproducible workflows

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📄 File Format Specification

https://github.com/yhoogstrate/fastafs/blob/master/doc/FASTAFS-FORMAT-SPECIFICATION.md

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🔗 Links

https://bio.tools/fastafs https://github.com/facebook/zstd/blob/dev/contrib/seekable_format/zstd_seekable_compression_format.md

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🧰 Installation

Dependencies

• libboost (unit testing)
• libopenssl / libssl
• libfuse
• zlib / libzstd
• C++ compiler (C++14+)
• cmake or meson + ninja

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Debian / Ubuntu

sudo apt install git build-essential cmake libboost-dev libssl-dev \
libboost-test-dev libboost-system-dev libboost-filesystem-dev \
zlib1g-dev libzstd-dev libfuse-dev

git clone https://github.com/yhoogstrate/fastafs.git
cd fastafs

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RHEL / CentOS / Fedora

sudo yum install git cmake gcc-c++ boost-devel openssl-devel \
libzstd-devel zlib-devel fuse-devel

git clone https://github.com/yhoogstrate/fastafs.git
cd fastafs

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Compile (recommended)

cmake -DCMAKE_BUILD_TYPE=release -DCMAKE_INSTALL_PREFIX=/usr/local .
make -j $(nproc)
sudo make install

Without root:

cmake -DCMAKE_BUILD_TYPE=release -DCMAKE_INSTALL_PREFIX=~/.local .
make -j $(nproc)
make install

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⚙️ Usage

Add FASTA to cache

fastafs cache test ./test.fa

Or from 2bit:

fastafs cache test ./test.2bit

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List cached datasets

fastafs list

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Mount archive

fastafs mount hg19 /mnt/fastafs/hg19
ls /mnt/fastafs/hg19

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Inspect sequences

fastafs info

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Running mounts

fastafs ps

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Mount via fstab

mount.fastafs#/path/to/file.fastafs /mnt/fastafs fuse auto,allow_other 0 0

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📚 Citation

If you use FastaFS in your research, please cite:

Hoogstrate, Y., Jenster, G.W. & van de Werken, H.J.G.
FASTAFS: file system virtualisation of random access compressed FASTA files.
BMC Bioinformatics 22, 535 (2021).
https://doi.org/10.1186/s12859-021-04455-3

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🤝 Contributing

Contributions are welcome!

• Open an issue
• Submit a pull request

Format code with:

make tidy

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💡 Final note

FastaFS does not replace FASTA or TwoBit — it enhances them by making them easier to use, more efficient, and seamlessly integrated into existing workflows.