| 摘要 |
PURPOSE:To reduce the movement of a head to the half for data access (seek), by providing a directory area between extents. CONSTITUTION:A data set area request given with a job control language is analyzed in an analyzing part 11, and one of idle areas, which are lrger than the requested data set area, out of idle areas of the whole of a disc is reserved as a data set area under the control of an area controlling part 13 for one data set by an area controlling part 12 for the whole of the disc, and a data set allocating part 14 sets the upper boundary and the lower boudary of the half of the requested quantity to the second extent of an area control table for one data set. The upper boundary and the lower boundary of the rest half in the position connected to the second extent are set to the first extent. A requested directory area is reserved between both extents by a reserving part 15. |
