A storage controller calculates an access frequency of each logical disk; that is selects a first logical disk device of which the access frequency exceeds a first predetermined value, the first logical disk device being allocated to a first physical disk device; selects a second logical disk device...http://www.google.de/patents/US7577815?utm_source=gb-gplus-sharePatent US7577815 - Apparatus and method for reallocating logical to physical disk devices using a storage controller, with access frequency and sequential access ratio calculations and display
