A data storage apparatus having improved data transfer performance. The storage apparatus has: plural controllers connected to each other by first data transfer paths; plural processors controlling the controllers; and second data transfer paths through which the controllers send data to various devices. Each of the controllers has a data-processing portion for transferring data to the first and second data transfer paths. The data-processing portion has a header detection portion for detecting first header information constituting data, a selection portion for selecting data sets having continuous addresses of transfer destination and using the same data transfer path from plural data sets such that a coupled data set is created from the selected data sets, a header creation portion for creating second header information about the coupled data set, and coupled data creation means for creating the coupled data set from the selected data sets and from the second header information.