Patent ID: 8375004
Filing Date: 2013-02-12
Classification: G06F

Abstract:
1. A storage system comprising: a first storage apparatus having a first controller with at least one processor for controlling processing, and a plurality of first storage devices configuring a first data volume storing data sent from a first host computer and a first journal volume storing journals, wherein each of the journals includes a sequential number and the data written to the first data volume; a second storage apparatus having a second controller with at least one processor for controlling processing, and a plurality of second storage devices configuring a second journal volume storing journals sent from the first storage apparatus asynchronously with access to the first data volume and a second data volume to which each of the journals stored in the second journal volume is reflected in order of the sequential number included in each of the journals; and a third storage apparatus having a third controller with at least one processor for controlling processing, and a plurality of storage devices configuring a third journal volume storing journals sent from the first storage apparatus asynchronously with access to the first data volume and a third data volume to which each of the journals stored in the third journal volume is reflected in order of the sequential number included in each of the journals; wherein if a failure occurs in the first storage apparatus, the second controller in the second storage apparatus compares a second sequential number in the latest reflected journal to the second data volume and a third sequential number in the latest reflected journal to the third data volume, if the third sequential number is newer than the second sequential number, the second controller in the second storage apparatus receives one or more differential journals from the third storage apparatus to write the received differential journals to the second journal volume, and if the second sequential number is newer than the third sequential number, the second controller in the second storage apparatus sends one or more differential journals to the third storage apparatus to write the sent one or more differential journals to the third journal volume.