Method and apparatus for copying data from a main site to a remote site

摘要

A disk subsystem assures the sequence and the coherence of data updating with two or more disk subsystems is provided with an asynchronous remote copy function. A main center 9 includes a computer system having the configuration of slave subsystems 3-2 to 3-n connected with a master disk subsystem 3-1. It secures the coherence between data at the main center 9 and the remote center 10 at the temporary suspension by repeating temporary suspension and release of the temporary suspension of the remote copy by the master subsystem 3-1 at predetermined opportunities. It also repeats temporary suspension and release of the temporary suspension of the remote copy by slave subsystems 3-2 to 3-n connected to it.