A computer system including: at least one host computer, a storage system for storing data used in the host computer, and a managing computer for managing storing the data in the storage system which are connected to each other with a network. The managing computer monitors the journal volume which is a storing destinations of the journal, in a case that the journal is stored in the journal volume in parallel, when it is detected that the storing destination of the journal changes from one of the groups into which the journal is just stored to another group, transmits an instruction to the storage system to change the storing destination of the journal to another group.