Abstract: The invention relates to methods and associated systems for managing application workloads and data storage resources. Data storage resources my be mapped to logical addresses associated with applications based on the I/O activity associated with those addresses. Techniques are disclosed for determining the I/O capacity of a data storage resource for a given workload and allocating resources according to administrator requirements. Various physical devices may be mapped to logical addresses by defining a composite volume for the application. The invention may be implemented as a transparent layer between the application and the data storage resource, for example, in the file system.