Remote data mirroring system

The method of protecting data contains the step which receives the data for memory from 1 or two or more data resources (24). This data is sent so that it may memorize to a primary storage device (28) and a secondary storage device (32). While waiting for the reference marker of data having been well memorized by the secondary storage device, the record relevant to this data is temporarily memorized by the disaster-proof storage unit (48) which adjoins a primary storage device. When the event which does damage to at least one copy of the data in a primary storage device happens, at least one copy of the data memorized by the record and secondary storage device which were memorized by the disaster-proof storage unit is used for this data, and it is reconstructed.