SeaweedFS

What is SeaweedFS?

SeaweedFS is an open source distributed storage system that stores objects, files, and data-lake tables behind an S3-compatible API. Written in Go and licensed Apache-2.0, it packs many small files into large volumes so reads usually take a single disk seek, letting one cluster hold billions of files on commodity hardware.

What is SeaweedFS best for?

SeaweedFS is best for teams that need to store and serve huge numbers of small-to-medium files — images, thumbnails, documents, logs, ML artifacts — cheaply and fast, on their own infrastructure. It suits self-hosted S3 storage, photo and media backends, Kubernetes persistent storage via its CSI driver, and hybrid setups that tier cold data to the cloud.

What can SeaweedFS do?

• Serve an S3-compatible object API (plus its own HTTP API), so existing AWS SDK and S3 tooling work against it.
• Store billions of files with O(1) disk reads by packing them into 32GB volumes with ~40 bytes of metadata per file.
• Add a Filer layer for directory structure, POSIX access via FUSE mount, WebDAV, and Hadoop compatibility.
• Back Filer metadata with your choice of store — MySQL, PostgreSQL, Redis, Cassandra, MongoDB, or Elasticsearch.
• Tier warm data to the cloud (S3, Google Cloud Storage, Azure, Backblaze) while keeping fast local access.
• Cut storage cost on cold data with erasure coding, and protect data with rack- and datacenter-aware replication.
• Run on Kubernetes through a CSI driver and operator, and replicate active-active across clusters.

Where does SeaweedFS fall short?

Its S3 API is broad but not a byte-for-byte AWS clone — advanced versioning and Object Lock have gaps, so double-check compliance-grade features before relying on them. The Filer needs an external metadata database (Postgres, Redis, and the like) that you run and back up separately from the object data. And some enterprise features — like automated recovery and self-healing — sit behind a commercial license, so the fully hands-off operation of managed cloud storage isn’t free out of the box.

Is SeaweedFS free?

Yes. The core distributed storage system is free and open source under the Apache-2.0 license — no per-request or per-GB fees, you only pay for the hardware you run it on. A separate commercial “SeaweedFS Enterprise” edition adds features like faster metadata, active-active replication tuning, and support, but the open source version is fully functional for self-hosted object storage.

What does SeaweedFS replace?

SeaweedFS is a self-hosted stand-in for managed cloud object storage — an Amazon S3, Google Cloud Storage, and Azure Blob Storage alternative. Because it speaks the S3 API, apps written for those services can point at a SeaweedFS endpoint instead, trading per-request cloud bills for hardware you own. It also overlaps with distributed filesystems like HDFS, Ceph, and MinIO.

FAQ

Is SeaweedFS open source? Yes. SeaweedFS is licensed under Apache-2.0 and developed in the open on GitHub, with the full distributed storage system, Filer, and S3 gateway available for free.

Can I self-host SeaweedFS for free? Yes. The open source edition is free to self-host with no usage fees; you only cover your own servers and storage. A paid enterprise edition exists but isn’t required to run a production S3-compatible cluster.

Is SeaweedFS a good S3 alternative? For self-hosted object storage at scale it’s a strong fit, especially for workloads dominated by many small files. Its S3 API covers common operations, though a few advanced features (strict versioning, Object Lock) are less complete than AWS.

What do I need to run SeaweedFS? A Linux host (or Kubernetes) and the single weed Go binary. A minimal cluster runs a master, one or more volume servers (~2–4 GB RAM each is typical), and — if you need directories or the full S3 filer — a Filer backed by a metadata database such as PostgreSQL or Redis.