The 12th IFIP/IEEE International Symposium on Integrated Network Management (IM), Trinity College Dublin, Ireland, May 23-27, 2011, discussed recent advances and prospective research directions in the areas of network, system, and service management. The theme of IM 2011 was 'Effective and Energy Efficient Management of Network and Services'. John Manley gave a retrospective on cloud computing, including projects at HP Labs Bristol on cloud-based animation feature films rendering. 'Cloud Computing: why 10 years?' delivered by Matt Hamilton of Ericsson, described current megatrends in mobile broadband networks and cloud computing. Jun Li, of HP Labs Palo Alto, presented his work on 'Managing Data Retention Policies at Scale'. The paper entitled 'Design and Evaluation of a Hierarchical Application Placement Algorithm in Large Scale Clouds', proposed a novel approach for cloud application placement in a hierarchical context.