Preparing CERN Tier-0 data centres for LHC Run 3

Since 2013 CERN’s local data centre combined with a colocation infrastructure at the Wigner data centre in Budapest [1] have been hosting the compute and storage capacity for Worldwide LHC Computing Grid (WLCG) [2] Tier-0. In this paper we will describe how we try to optimize and improve the operation of our local data centre to meet the anticipated increment of the physics compute and storage requirements for Run 3, taking into account two important changes on the way: the end of the co-location contract with Wigner in 2019 and the loan of 2 out of 6 prefabricated compute modules being commissioned by the LHCb experiment [3] for their online computing farm.