Data storage apparatus and data reading method

A data storage apparatus using a plurality of hard disk drives for storing stream data includes a command receiving portion for receiving a stream data read command from the outside; and a data processing portion reading the stream data stored in the hard disk drives upon receiving the read command, assembling the data, and transferring the assembled stream data to the outside. The apparatus further includes a control portion performing control of determining maximum time from receiving the read command to completing the assembly of the stream data, terminating the data read from the hard disk drives in the case where the maxim time has elapsed, and preparing the stream data transferred to the outside in the data processing portion only using data having been read; and a managing portion variably setting the maximum time according to a bit rate of the stream data read on the read command.