For maintaining a context stack, a processor monitors a stack size for a stack of a plurality of existing contexts that are not associated to a process of a plurality of processes. Each context is associable and reusable with a plurality of processes and includes a pathway to a data set when not associated to any process of the plurality of processes. The pathway includes a logical volume identifier for the data set, a logical address of the data set within the logical volume, and a logical address of an intervening device. The context defines communications between the process and the data set through the pathway when associated to the process, and each context is returned to the stack when not associated to the process.