Performance of the LHCb detector during the LHC proton runs 2010-2012

The LHCb experiment takes data at the Large Hadron Collider at CERN. During the 2009-2012 running period the performances of the detector have been assessed with pp collision data. The tracking and particle identification capabilities reached and exceeded the design specifications, despite the harsher conditions. The LHCb detector operation and its performance are discussed as measured in data from the first LHC run.