MinIO: Overview for developers. Why you need it, pros, cons, and alternatives
Published on 2025-10-25
In the world of modern applications, especially in the era of AI and big data, storing unstructured data is a key challenge. MinIO is a high-performance object storage distributed under the AGPLv3 license. It is fully compatible with the Amazon S3 API and allows you to deploy storage locally or in the cloud. Designed to scale to exabytes, MinIO is ideal for AI/ML workloads, analytics and web applications. In this article we’ll cover why it’s useful for a developer, evaluate pros and cons, and look at alternatives.
Why MinIO for a developer?
As a developer, you often face the need to store files, images, videos or datasets for machine learning. Traditional file systems (NFS, SMB) don’t handle scale well, and cloud services like AWS S3 add latency and provider lock-in. MinIO addresses these issues by offering self-hosted S3-compatible storage.
Key reasons to use MinIO:
- High S3 compatibility. Thanks to compatibility with the main S3 API, you can use libraries like
boto3(Python) or the AWS SDK with almost no changes. Just point the endpoint to MinIO instead of S3. (Important: full compatibility with all S3 ecosystem services, such as Object Lambda, is not guaranteed.) - For AI and ML. MinIO is optimized for exabyte workloads and integrates with PyTorch, Apache Iceberg and other frameworks.
- Control and deployment. You can deploy MinIO on your own servers (Kubernetes, Docker) and get full control over your data.
- Flexibility and fault tolerance.
MinIO runs in two modes:- Standalone — for local development, a single binary.
- Distributed — for production, requires a minimum of 4 drives and uses Erasure Coding, distributing data and parity blocks across drives. This provides fault tolerance without classic replication.
For a developer MinIO is a powerful tool for prototyping and scaling. However, it’s important to remember: using MinIO for commercial purposes under AGPLv3 requires caution.
Pros and cons of MinIO
| Aspect | Pros | Cons |
|---|---|---|
| Performance | High throughput, optimized for NVMe. Ideal for AI and high-performance workloads. | Performs poorly with HDDs. Background checks create IO overhead — a conscious design trade-off. |
| Scalability | Efficient Erasure Coding, easily scales in a flat-namespace. | Requires at least 4 drives for production. Not suitable for single-server setups. |
| Convenience | Easy deployment in Docker/K8s, high S3 compatibility. | Problems with millions of small files. Each object has metadata and parity information. |
| Economics and license | There is enterprise 24/7 support. | The main downside — the AGPLv3 license. If you use MinIO as a backend for a web service (SaaS), you are required to disclose the source code of your service. For most commercial projects this means purchasing a paid enterprise license. |
| Integration | Support for AI ecosystem (PyTorch, Iceberg). | Only object storage. No block or file API like Ceph. |
Alternatives to MinIO
If MinIO is not suitable — for example, due to license or storage characteristics, consider other solutions:
| Alternative | Type | Pros | Cons | When to choose |
|---|---|---|---|---|
| AWS S3 | Cloud | De-facto standard, virtually unlimited scale, AWS integrations. | Expensive, egress traffic is paid, provider lock-in. | Cloud-native applications without self-hosting. |
| Ceph RGW | Self-hosted | Unified storage (block, file, object), flexibility. | Complex management, high overhead. | For large data centers. |
| SeaweedFS | Self-hosted | Optimized for small files, S3-compatible, Apache 2.0 license. | Fewer enterprise features. | For cheap, simple clusters. |
| Garage | Self-hosted | Excellent geo-replication, minimal requirements, AGPLv3. | No UI, limited features. | For edge setups and low-power clusters. |
| Google Cloud Storage | Cloud | Cheaper than S3, strong analytics. | Lock-in, weak S3 compatibility. | For GCP projects. |
| Azure Blob | Cloud | Integration with Azure, tiered storage. | Latency outside Azure, complex pricing. | Microsoft ecosystem. |
Conclusion
MinIO is an excellent solution for those who value performance and S3 compatibility. But before adoption it’s important to consciously assess the risks of the AGPLv3 license.
If your project is open source or you are ready to purchase an enterprise license, MinIO will be an ideal choice.
If you’re looking for a free closed S3 storage, consider SeaweedFS or Ceph — they offer more freedom in terms of licensing and architecture.
📚 Further reading