A system and method for allocating resources on a shared storage system are disclosed. The system 10 can include a shared storage device 12 and a plurality of port schedulers 14 associated with a plurality of I/O ports 16 that are in communication with the shared storage device 12. Each port scheduler 14 is configured to enforce a concurrency level and a proportional share of storage resources of the shared storage device 12 for each application 18 utilizing the associated port. The system 10 can also include a resource controller 17 that is configured to both monitor performance characteristics of the applications 18 utilizing at least one of the I/O ports 16, and to adjust the concurrency level and the proportional share of storage resources parameters of the port schedulers 14 for at least a portion of the applications 18 in order to vary allocation of the resources of the shared storage device 12.