Patent ID: 8909848

Claim:
An information system, comprising: a computer; a storage system, which includes a plurality of flash memory devices and a storage controller coupled to the flash memory devices, wherein each of the flash memory devices includes a plurality of providing areas and one or more surplus areas, the providing areas are storage areas provided by the flash memory device, and the surplus areas are storage areas used as alternatives to the providing areas when one or more of the providing areas are unused for storing data, and the surplus areas are physically or logically separately secured from the providing areas, wherein the storage controller is configured to: (a) define a plurality of logical components using the providing areas of the flash memory devices, with storing relations between the flash memory devices and the logical components being configuration information; (b) process an I/O request from the computer, comprising converting an address designated by the I/O request to an address of at least one of the logical components and converting the address of the at least one of the logical components to an address of at least one of the flash memory devices, according to the configuration information; and (c) for each of the flash memory devices, store a surplus capacity value based on a capacity of the surplus areas in the each of the flash memory devices, and a management system configured to: (A) receive an operation request, which designates at least one logical component; and (B) display a management surplus capacity value about the designated logical component, which indicates that a degenerating risk or blockage risk of the designated logical component is increased when the management surplus capacity value becomes close to a defined value, wherein the management system or the storage controller is configured to calculate the management surplus capacity value by: (1) selecting one or more flash memory devices among the flash memory devices related to the designated logical component, by referring to the configuration information; (2) acquiring one or more surplus capacity values corresponding to the one or more flash memory devices selected in the (1); and (3) statistically calculating the management surplus capacity value, wherein the statistically calculating of the the management surplus capacity value comprising selecting a second smallest value from the one or more surplus capacity values acquired in the (2).