LHCb commissioning and operation

The LHCb detector was commissioned with beam in November and December 2009. The time alignment was performed and data for space alignment taken both with and without magnetic field. When data taking was restarted in 2010, a second iteration on time and space alignment was performed. The resulting detector performance lead amongst others to good invariant mass resolution, as could be demonstrated in the $\lambda$ measurement yielding m=1115$\pm$2.5 MeV/c$^2$. This article will report on procedures used and progress in commissioning the detector for the first LHC physics run.