Patent ID: 7401196

Claim:
A storage system, connected to a plurality of host computers, comprising: a plurality of storage device groups having storage areas, comprising a plurality of storage area units; a control block group, used to control exclusion of access to each of the storage area units by the plurality of host computers; storage resources configured to store the control blocks; and a controller, which executes the exclusion control using the control block group, wherein each of the plurality of storage device groups comprises one or more storage devices, the control block group comprises one or more control blocks, each control block corresponds to one among the plurality of storage device groups, and has a plurality of control sub-blocks to perform access exclusion control for one storage area unit, the controller ascertains the number of host computers which is the number of host computers actually able to access the same storage area units and/or the number of groups which is the number of storage device groups among the plurality of storage device groups for which the exclusion control is necessary, and based on the ascertained number of host computers and/or number of groups, constructs the control block group, the controller has a control interface which accepts, from at least one host computer among the plurality of host computers or from another computer machine connected to the storage system, input of the number of host computers and/or of the number of groups, and, by accepting input of the number of host computers and/or of the number of groups from the control interface, ascertains the number of host computers and/or the number of groups, the sizes of the control sub-blocks are larger when the number of host computers for which access exclusion control is performed using the control sub-blocks is greater, and the controller computes the number of the control sub-blocks which can be stored in an area based on the ascertained number of host computers and the size of the area for storage of the control block group in the storage resources, and notifies the host computer and/or said another computer machine of the computed number.