Obstor vs XtreemFS

Obstor is an Apache 2.0-licensed, S3-compatible object storage server with built-in SFTP support. It works with S3 SDKs, command-line tools, and applications without code changes. In distributed deployments, objects are sharded and replicated across connected nodes, with each object kept in at least two global locations. Its native SFTP server stores uploaded files as S3 objects. Data features include SSE-C and SSE-S3 server-side encryption with KMS integration, configurable erasure coding for drive and node failures, and object versioning with lifecycle policies. IAM controls use users, groups, policies, and service accounts with S3 and AWS IAM policy syntax. Event notifications can be sent to Kafka, NATS, AMQP, Redis, PostgreSQL, Elasticsearch, and webhooks. Installation options include a single binary, Docker, a Kubernetes Helm chart, or building from source. Standalone instructions cover macOS, GNU/Linux, and 64-bit Windows. Standalone servers are intended for development and evaluation; versioning, object locking, and bucket replication require distributed deployment with erasure coding.

XtreemFS is a free, fault-tolerant distributed file system for general-purpose storage, available for Linux, macOS, Windows and self-hosted deployments. Files are replicated across storage servers, with automatic failover to a backup replica if the primary fails. Full or partial read-only replicas support immutable files and can be used to create caches across datacenters. The project says an installation can grow to thousands of storage and metadata servers by adding or removing storage servers. POSIX compatibility makes it usable as an NFS replacement. SSL and X.509 certificate support are built in, and the site says XtreemFS can run over the internet without a VPN. A Hadoop client supports use as an HDFS replacement. Listed uses include filer replacement, HPC and Hadoop clusters, VM block storage and cross-branch sharing. Linux distribution packages and precompiled Windows and Mac OS X clients are available. The FAQ says a single volume may hold up to tens of millions of files, with no known limits stated for volumes and services. The project is open source under a BSD license and is developed by Zuse Institute Berlin.