CERN Accelerating science

EOS Service - CERN

EOS Open Storage

CERN storage technology

used at the Large Hadron Collider (LHC)

EOS Community 2019 Workshop Latest V4.5.6

About EOS

EOS provides a service for storing large amounts of physics data and user files, with a focus on interactive and batch analysis

Elastic, Adaptable and Scalable

EOS is a software solution for central data recording, user analysis and data processing.

EOS supports thousands of clients with random remote I/O patterns with multiprotocol support

EOS offers a variety of authentication methods
KRB5, X509, Shared Secret and UNIX

Over 250 PB of raw disk space at CERN

Designed for High-Capacity and Low-Latency provides access to over 1.8B files stored on more than 1.2k nodes and 50k disks at CERN.

CERN Services



CERN source code repository


Public source code repository


EOS bug tracker

CI on GitLab

Continous integration platform


EOS software repositories


Community Forum for EOS related topics.

Want to know more?

Our Collaborations

Latest News

Last news of the Cern Data Center and Eos workshops will be published here.

Third EOS Workshop at CERN

on Feb 5-6, 2018

After two successful editions with over 70 participants we are preparing the third edition to present the project evolution and future road map. We welcome our community to exchange their experiences and best practices in running EOS as a storage service.

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AARNet and CERN sign MOU

on Sep 20, 2017

AARNet and CERN (the European Organization for Nuclear Research) recently signed a formal agreement which establishes a framework for ongoing collaborations to develop cloud storage technologies for the benefit of scientific and education communities globally.

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CERN Data Centre passes the 200-petabyte milestone

on Jun 29, 2017

The CERN Data Center passed the milestone of 200 petabytes of data permanently archived. Particles collide in the LHC detectors approximately 1 billion times per second, generating about 1 petabyte of collision data per second.

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