Arrangement and method for reallocation of logical to physical disk devices using a storage controller

The storage controller (104) is connected to a service processor (111), calculates an access characteristic (500) of each logical disk (200), presents the calculated access characteristic via the service processor to a service person, and receives an input indicating reallocation. Then, when the access characteristic of a first logical disk allocated to a first physical disk exceeds a predetermined value whereas the access characteristic of a second logical disk allocated to a second physical disk having higher speed than the first physical disk is less than the predetermined value, the first and second logical disks are reallocated to, respectively, the second and first physical disks.