Speaker
Luca Mascetti
(CERN)
Description
CERN IT DSS operates the main storage resources for data taking and physics analysis mainly via three system: AFS, CASTOR and EOS. The total usable space available for users is about 100 PB (with relative ratios 1:20:120). EOS deploys disk resources across the two CERN computer centres (Meyrin and Wigner) with a current ratio 60% to 40%. IT DSS is also providing sizable on-demand resources for general IT services most notably OpenStack and NFS clients. This is provided by our Ceph infrastructure and a few of proprietary servers (NetApp) for a total capacity of ~1 PB.
We will describe our operational experience and recent changes to these systems with special emphasis to the following items:
- Present usages for LHC data taking (new roles of CASTOR and EOS)
- Convergence to commodity hardware (nodes with 200-TB each with optional SSD) shared across all services
- Detailed study of the failure modes in the different services and approaches (RAID, RAIN, ZFS vs XFS, etc...)
- Disaster recovery strategies (across the two CERN computer centres)
- Experience in coupling commodity and home-grown solution (e.g. Ceph disk pools for AFS, CASTOR and NFS)
- Future evolution of these systems in the WLCG realm and beyond
Author
Luca Mascetti
(CERN)
Co-authors
Alessandro Fiorot
(CERN)
Andrea Ieri
(CERN)
Belinda Chan Kwok Cheong
(CERN)
Dan van der Ster
(CERN)
Giuseppe Lo Presti
(CERN)
Herve Rousseau
(CERN)
Hugo Gonzalez Labrador
(University of Vigo (ES))
Dr
Jakub Moscicki
(CERN)
Jan Iven
(CERN)
Massimo Lamanna
(CERN)
Sebastien Ponce
(CERN)
Dr
Xavier Espinal Curull
(CERN)
