Patent ID: 7246214
Filing Date: 2007-07-17
Classification: G06F,Y10S

Abstract:
1. A remote copy method in a storage system comprising a first storage sub-system configured for communication with a host system and operative to exchange data with the host, a second storage sub-system in data communication with the first storage sub-system, and a third storage sub-system in data communication with the first storage sub-system, the method comprising: receiving a first write request from the host to store first data on the first storage sub-system, the first data comprising one or more first blocks of data, each first block of data being associated with a block address; in response to receiving the first write request, transferring the first data from the first storage sub-system to the second storage sub-system; receiving a second write request from the host to store second data on the first storage sub-system, the second data comprising one or more second blocks of data, each second block of data being associated with a block address; in response to receiving the second write request, transferring the second data from the first storage sub-system to the second storage sub-system; and subsequent to receiving the first write request and the second write request, transferring at least portions of both the first data and the second data to the third storage sub-system, wherein if any of the first data blocks and the second data blocks have the same block address, then for each such pair of data blocks transferring only the second data block.