EOS project.



EOS is a software solution that aims to provide fast and reliable multi-PB disk-only storage technology for both LHC and non-LHC use-cases at CERN. The core of the implementation is the XRootD framework which provides feature-rich remote access protocol. The storage system is running on commodity hardware with disks in JBOD configuration. It is written mostly in C/C++, with some of the extra modules in Python. Files can be accessed via native XRootD protocol, a POSIX-like FUSE client or HTTP(S) & WebDav protocol.


The most up to date documentation can be found at: http://eos.readthedocs.org/en/latest/

Doxygent documentaion of the API is available in the ./doc directory and can be generated using the following command:

# Inside the EOS git clone directory
cd doc
# Documentation generated in the ./html directory which can be accessed using any browser
# file:///eos_git_clone_dir/doc/html/index.html

Project Directory Structure

  • archive - Archive tool implementation in Python
  • auth_plugin - Authorization delegation plugin
  • authz - Authorization capability functionality
  • cmake - CMake related scripts and functions
  • common - Common helper files and classes
  • console - Command line client implementation
  • doc - Doxygen documentation
  • etc - Service scripts, logrotation and sysconfig Files
  • fst - The Storage Server Plugin (FST)
  • fuse - The FUSE mount Client (eosd low level API)
  • man - Manual pages
  • mgm - Meta Data Namespace and Scheduling Redirector Plugin (MGM)
  • mq - Message Queue Server Plugin
  • namespace - Namespace Implementation
  • nginx - Nginx related patches for EOS integration
  • srm - SRM BestMan utility scripts
  • sync - EOSHA high availability daemon + file/directory synchronization programs
  • test - Instance test script with some dedicated test executables
  • utils - Usefull utilities and the uninstall scripts
  • var - Placeholder directory to create log, http and namespace directories


  yum install -y git gcc cmake readline readline-devel fuse fuse-devel \
leveldb leveldb-devel zlib zlib-devel libattr libattr-devel libuuid libuuid-devel \
xfsprogs xfsprogs-devel sparsehash sparsehash-devel e2fsprogs e2fsprogs-devel \
libmicrohttpd libmicrohttpd-devel openssl openssl-devel openssl-static \
ncurses ncurses-devel ncurses-static protobuf-devel cppunit-devel openldap-devel \
hiredis-devel zeromq-devel jsoncpp-devel xrootd xrootd-server-devel xrootd-client-devel
xrootd-private-devel cppzmq-devel libcurl-devel


To build EOS, you need gcc (>=4.4) and CMake installed on your system:

# Note that you will also need to check out the fmd and qclient git submodules
git submodule update --init --recursive
# Create build workdir
mkdir build
cd build
# Run CMake
cmake ..
# Build
make -j 4


The default behaviour is to install EOS at system level using CMAKE_INSTALL_PREFIX=/usr. To change the default install prefix path, do the following:

# Modify the default install path
cmake ../ -DCMAKE_INSTALL_PREFIX=/other_path
# Install - might require sudo privileges
make install
# Uninstall
make uninstall

Source/Binary RPM Generation

To build the source/binary RPMs run:

# Create source tarball
make dist
# Create Source RPM
make srpm
# Create RPMS
make rpm

System specific notes

  • The current production version of EOS in the beryl_aquamarine branch which has a hard requirement on XRootD 3.3.6.
  • The the future production version of EOS is the citrine branch and requires XRootD >= 4.2.0.

Bug Reporting

You can send EOS bug reports to project-eos@cern.ch. The preferable way, if you have access, is use the online bug tracking system Jira to submit new problem reports or search for existing ones: https://its.cern.ch/jira/browse/EOS


EOS - The CERN Disk Storage System
Copyright (C) 2015 CERN/Switzerland
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY, without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.