Patent ID: 8473465

Claim:
A storage system comprising: a first storage unit having intercepting means for intercepting data operations received by said first storage unit, a storage array in communication with said intercepting means, and a buffer connected to said intercepting means, said buffer stores write operations for latter transmission to said second storage unit; a second storage unit having a storage array; a third storage unit having a storage array; and means for controlling said communication links between said first storage unit, said second storage unit, and said third storage unit such that said first storage unit and said second storage unit are set to be in communication during normal operations and said second storage unit and said third storage unit are in communication during a back-up period of time; and said intercepting means sends data operations performing a write to said second storage unit and said storage array of said first storage unit, and said buffer and said first storage array in said first storage unit provide two discrete communication paths for data operations to travel where one communication path is between said intercepting means through said buffer on said first storage unit to said second storage unit when said second storage unit is in communication with said first storage unit and said second communication path is from said intercepting means to said storage array in said first storage unit, wherein said communication path between said intercepting means and said buffer is on a dedicated connection isolated from said second communication path.