LHCb Computing Resource usage in 2010

This notes summarizes the uses of computing resources during 2010 as support document for the report due to CRRB by March 1st 2011. Computing resources are requested to WLCG and pledged by the sites to be available as of April 1st of the corresponding year. Official WLCG accounting portals have a granularity of 1 month. Thus, the present document covers the period from April 1st 2010 until February 1st 2011. The data used in the following sections is taken from either the WLCG accounting portal: https://www3.egee.cesga.es/gridsite/accounting/CESGA/egee_view.php, or from the LHCb DIRAC Accounting portal: http://lhcbweb.pic.es/DIRAC/LHCb-Production/visitor/systems/accountingPlots/job, in what respect usage of CPU resources. For the usage of the Storage resources snapshots of the situation as seen by the SLS sensors: https://sls.cern.ch/sls/service.php?id=LHCb-Storage, and the DIRAC StorageUsage Service: dips://lhcb-serv1-dirac.cern.ch:9151/DataManagement/StorageUsage is used.