According to the present invention, as regards a computer system that uses virtual storage management, because content of auxiliary storage utilized by paging is used, dump information can be obtained by outputting only a part of the content of the auxiliary storage at the time of occurrence of an abnormal system condition. As a result, time required to restart the computer system and business can be shortened. What is more, because it is not necessary to add a special external storage for obtaining dump information, computer resources can be utilized more efficiently.