Commissioning of the ATLAS inner detector with cosmic rays

Several million cosmic events were recorded during the combined ATLAS runs in autumn 2008. Using these cosmic ray events, the software infrastructure of the ATLAS Inner Detector is being commissioned. The full software chain has been set up in order to reconstruct and analyse these kind of events. Different pattern recognition algorithms, track fitters and various calibration methods have been developed and validated. The infrastructure to deal with conditions data coming from the data acquisition and detector control system as well as calibration runs has been put in place, allowing to apply alignment and calibration constants. Stable software is essential to ensure the continuous monitoring of the detector performance during data taking. Detector efficiencies, noise occupancies and resolutions are studied in detail as well as the performance of the track reconstruction itself.