Calcul Québec is transitioning their high performance computing cluster from using Grid Engine to Moab for resource management and scheduling. Their cluster, Colosse, has 960 diskless compute nodes with 7,680 cores and 1PB of storage. They have implemented Moab on a test partition so far and are progressively increasing the number of nodes under Moab's control while Grid Engine and Moab coexist for a few months. The transition has involved reworking management scripts, training users and staff, and ensuring Moab can support their existing scheduling policies and share tree allocation model.