1. A computer system comprising: a first storage system having a plurality of first storage areas capable of storing data used by a first host computer via a first communication line, a first control portion connected with a plurality of disk units forming the first storage areas, and a first memory connected with the first control portion; a second storage system having a plurality of second storage areas capable of storing data used by a second host computer via a second communication line and a second control portion connected with disk units forming the second storage areas, the second storage system being connected with the first storage system via a third communication line; a third storage system connected with the first storage system via a fourth communication line, having a plurality of third storage areas for storing copy of data stored in the first storage areas of the first storage system; and a fourth storage system connected with the second storage system via a fifth communication line and with the third storage system via a sixth communication line, having a plurality of fourth storage areas for storing copy of data stored in the second storage areas of the second storage system, wherein the first control portion controls access from the first host computer to the data stored in the first storage areas and transmission of the copy of data stored in the first storage areas to the third storage system via the fourth communication line, in which the first and the third storage areas are formed as a first pair relation, wherein the second control portion controls access from the second host computer to data stored in the second storage areas and transmission of the copy of data stored in the second storage areas to the fourth storage system via the fifth communication line, in which the second and the fourth storage areas are formed as a second pair relation, wherein the first control portion manages the first pair relation and the second pair relation as a first group, wherein the first control portion gains first status information of the first pair relation, issues a request of second status information of the second pair relation to the second storage system, gains the second status information from the second storage system, and holds the first status information and the second status information as group status information in the first memory, wherein the first control portion sends the group status information to the first host computer, when the first control portion receives a request of gaining the group status information from the first host computer, wherein the group status information is an information table in which status of each pair registered in a group is indicated by the number of pairs of each status, wherein the first and second status information each indicates one of seven statuses in copy pairs including initial, during copy, duplexed, under suspension, suspended, pair being broken, and error statuses, wherein the initial status is a status in which copy is not started, the during copy status is a status of initial copy in which contents of a volume of a copy source of a pair have not been yet completely transferred to a volume of a copy destination, the duplexed status is a status in which contents of a volume of a copy source of a pair have been completely transferred to a volume of a copy destination, under suspension status is a transient status in which a copy is being temporarily stopped, suspended status is a status in which a copy has been temporarily stopped, pair being broken status is a transient status occurring when a copy is ended, and the error/no error status makes a transition when a fault occurs during copy, wherein said host after gaining copy status information judges copy status and to judge the copy status, a decision table for judging the copy status is used, said decision table having information concerning the copy status of a group and group container copy status information, and wherein processing for judging the copy status includes: extracting status information about each storage array controller and typical error information from the gained group container copy status information; classifying the extracted status information about the storage array controllers according to copy pair status and calculating the number of pairs in the same copy pair status; after the calculation, comparing the result of the calculation the numbers put in the copy status decision table; where the result of the comparison indicates that the copy pair status is not error, assigning the status put in the copy status decision table showing a coincidence as the copy status of the group container and ending processing; and where the copy pair status is error, referencing the group container copy status information, identifying a storage array controller having a typical error information, gaining the typical error information of the storage array controller, notifying the error information to the host and ending processing.