Abstract: A peripheral data storage system employing a data buffer connected to a plurality of data storage devices, such as tape recorders, dynamically reallocates data buffer storage segments among the various data storage devices. A normalized elapsed-time period is established based upon the number of accesses to the data storage devices. When the number of accesses reaches a threshold the need for dynamic reallocation is examined. During the elapsed-time period the system monitors which of the allocated buffer segments have any data transfer activity at all and also measures the intensity of the activity for the respective buffer segments. In a peripheral system, the intensity is indicated by the number of channel command retries submitted to a connected host processor for the respective allocated buffer segment. Based upon the allocation status of the buffer segments and intensity of activities of the respective buffer segments, the buffer allocations are selectively reallocated among the data storage devices.