Patent ID: 8250284

Claim:
An information system comprising: a local site including; a first storage device communicatively coupled to a first host computer and that stores data sent from the first host computer in a first volume, a management device communicatively coupled to the first storage device, a remote site that is a destination of write data from the local site, including, and a second storage device communicatively coupled to a second host computer and that stores data to be accessed from the second host computer in a second volume, wherein the management device calculates a capacity of the first volume used for update correlated with an update time and date as an update history of the capacity, and finds, based on the update history of the capacity, a capacity of the second volume to be required after a predetermined period of time, wherein the second storage device includes a second virtual volume and, according to a request of data write into the second virtual volume, dynamically allocates a storage area from the second volume in units of page, wherein the management device includes a memory in which address information storing an address of a base volume which is a volume storing a state of the first volume at a particular point of time, an address information storing an address of a differential volume storing an update difference of the first volume after the particular point of time, information of update time and date of the base volume, and information of update time and date of the differential volume, based on the address information of the base volume, the address information of the differential volume, the information of update time and date of the base volume, and the information of update time and date of the differential volume stored in the memory, the management device acquires a range of address where the base volume and the differential volume are stored and the update times and dates, wherein the management device calculates, as the update history of the volume, a capacity of the first volume used for update from the range of address correlated with the update times and dates, wherein the management device predicts a capacity of the second volume to be required for data write from the first volume after a predetermined period of time based on the update history of the volume, and wherein the output device outputs a graph showing, in a time series manner, the update history of the volume and a capacity of the second volume to be required for data copy from the first volume after a predetermined period of time, the capacity predicted based on the update history of the volume.