Patent ID: 7519768

Claim:
A computer system comprised of a host computer, at least one storage device which stores data to be used by said host computer on a plurality of volumes, and a management computer which controls said storage device, wherein said management computer includes: a memory, a processor to perform control, an interface to input and output data to said storage device, a volume allocation change program to change an allocation of volumes in said storage device to provide logical unit numbers for the volumes that are recognized by said host computer and allocations of virtual volumes in which predetermined ones of said volumes are allocated virtually to said host computer; an identification information management table to manage identification information of said storage device; and a port management table to manage a port of said storage device, which tables are provided in said memory, wherein said processor executes said volume allocation change program to control timing of notifying said host computer of an access start to one of said volumes such that said timing is differentiated depending on whether said volume is one of said virtual volumes at a time of setting security to a path between said host computer and said volume, wherein said processor executes said volume allocation change program to: perform the control to the access from said host computer to a real volume that is not one of said virtual volumes such that an access start is notified to said host computer after receiving one security setting completion notice from a storage device that provides said real volume to said host computer when the security is set to a path between said host computer and said real volume, and perform control to the access from said host computer to said one of said virtual volumes such that an access start is notified to said host computer after receiving two or more security setting completion notices from two or more storage devices that provide said virtual volume to said host computer when the security is set to paths between said host computer and said virtual volume and between said virtual volume and a real volume corresponding to said virtual volume, wherein said two or more security setting completion notices are received from a virtualized device that provides said virtual volume to said host computer and a storage device that provides the real volume corresponding to said virtual volume, which are included in said two or more storage devices, and wherein said processor executes said volume allocation change program to change over to another path which is a path between said host computer and a storage device that provides the real volume corresponding to said virtual volume and to which said security can be set when a path between said virtual volume and the real volume corresponding to said virtual volume is a path to which the security can not be set.