Various aspects of a data volume or other shared resource are determined and updated dynamically for purposes such as to provide guaranteed qualities of service. For example, the number of partitions in a data volume and/or the way in which data is stored across those partitions can be updated dynamically without significantly impacting the customer using the volume. The data stored to the volume can be striped or otherwise distributed across a number of logical areas, which then can be distributed across the partitions. Separate mappings can be used for the data in each logical area, and the logical areas in each partition, such that when moving a logical area only a single mapping has to be updated, regardless of the amount of data in that logical area. Further, logical areas can be moved between partitions without the need to repartition or redistributed the data in the data volume.