Remote dual copy of data in computer systems

摘要

A method and apparatus for achieving remote dual copy of data in a computer system (100) provides for data from a first storage device (104) to be copied onto a second storage device (106) that is located a great distance from the first storage device (104). A cache processor (128) is used at the site of the first storage device (104) to form a record of data written to the first storage device (104), by a host processor (102) at the site. The record is transmitted to a second cache processor (138) at the distant site. The second cache processor (138) uses the record to update the second storage device (106) whereby an identical copy of data on the first storage device (104) is maintained. Another aspect of the invention allows data to be migrated via a cache processor between storage devices at a same location so that servicing and non-disruptive tape backup may be performed on one of the devices.