Patent ID: 6915381

Claim:
A storage control and switch unit for transferring data between a host computer and first, second, third and fourth storage media, said storage control and switch unit comprising: a first storage controller having an operative point-to-point connection with each of said first and second storage media to manage arrays on said first and second storage media and having an inoperative point-to-point connection to each of said third and fourth storage media; a second storage controller having an operative point-to-point connection with each of said third and fourth storage media to manage arrays on said third and fourth storage media and having an inoperative point-to-point connection to each of said first and second storage media; first, second, third and fourth switches logically interposed between said first, second, third and fourth storage media, respectively, and said first and second storage controllers to select which point-to-point connection to each storage media is operative and which point-to-point connection to the storage media is inoperative; and means, responsive to failure of one of said storage controllers, for directing the other storage controller to change the operable switches of said one storage controller to inoperable and chance the inoperable switches of said other storage controller to operable and granting said other storage controller management authority for the arrays controlled by said one storage controller before said failure; and wherein said granting means includes a table which includes first, second, third and fourth identifiers for said first, second, third and fourth storage media, respectively.