Remote copy system

A remote copy system comprising:

• a plurality of first storage systems, each comprising a first control section to be coupled to a computer, a first logical volume, and a first storage area for storing data to be transmitted to a second storage system;
• and
• a plurality of second storage systems, each coupled to a first storage system and comprising a second control section, a second logical volume, and a second storage area for storing data received from the first storage system,
• wherein a plurality of pairs, each including a first logical volume for storing data received from the computer and a second logical volume for storing replicate data of data in the first logical volume, are configured between the plurality of first storage systems and the plurality of second storage systems,
• wherein when a first control section of a first storage system receives a write request from the computer, the first control section stores write data, which is to be stored in a first logical volume included in a pair according to the write request, and write order information assigned to the write data in a first storage area of the first storage system, and transmits a write completion report to the computer,
• wherein when one of the plurality of first storage systems instructs the rest of the plurality of first storage systems to defer operations for executing write requests, the operations for executing write requests are deferred in the plurality of first storage systems, the one of the plurality of first storage systems sends information related to a marker to the rest of the plurality of first storage systems, and each first control section stores a marker and the write order information assigned to the marker in a first storage area of a first storage system including the first control section, and the operation for executing write requests are restarted in the plurality of first storage systems,
• wherein a second control section of a second storage system, which includes a second logical volume included in a pair, issues a transmission request to a first storage system, which includes a first logical volume included in the same pair as the second logical volume repeatedly, so that in response to one or more transmission requests issued from the second control section, both the write data with the write order information and the marker with the write order information are transmitted from the first storage system to the second storage system, and the second control section stores the write data with the write order information and the marker with the write order information in a second storage area of the second storage system, and
• wherein when one of the plurality of second storage systems instructs the rest of the plurality of second storage systems to store write data to second logical volumes, each second control section controls to store write data from a second storage area of a second storage system including the second control section to a second logical volume of the second storage system, according to the write order information assigned to the write data, until reaching the marker.