Patent ID: 7457929
Filing Date: 2008-11-25
Classification: G06F,Y10S

Abstract:
1. A storage system comprising: a first disk array system coupled to a host computer and having a first cache memory, a first controller and a plurality of first disk drives, said first disk drives being configured as a first volume and a second volume; a second disk array system coupled to said first disk array system and having a second controller and a plurality of second disk drives, said second disk drives being configured as a third volume; and a third disk array system coupled to said first disk array system and having a third controller and a plurality of third disk drives, said third disk drives being configured as a fourth volume; wherein said first controller receives an update data sent from said host computer via the first cache memory to said first volume and stores a first data corresponding to said update data in said first volume, and backs up the update data from the first cache memory as a second data corresponding to said first data in said second volume, and then releases the update data from the first cache memory to release space therein; wherein said first controller transfers said second data from said second volume to both said second disk array system and said third disk array system via the first cache memory, and then releases the second data from the first cache memory to release space therein; wherein said second controller receives said second data from said first disk array system and backing up said second data in said third volume; and wherein said third controller receives said second data from said first disk array system and backing up said second data in said fourth volume.