Patent ID: 7441096
Filing Date: 2008-10-21
Classification: G06F

Abstract:
1. A method for managing a hierarchical storage system including a first storage unit, the first storage unit including a storage area to store data, a storage controller to control access to the storage area, and a communication interface to communicate with a file server, the method comprising: receiving an instruction from a file migration program of the file server to migrate a first file stored in a first portion of a first tier storage region defined by one or more first tier physical storage devices, the first tier storage region including a different portion for storing a second file therein; determining a first storage address corresponding to the first portion of the first tier storage region; and copying data stored at the first storage address to a second storage address corresponding to a second portion of a second tier storage region defined by one or more second tier physical storage devices, wherein the first and second tier physical storage devices provide different performance characteristics, wherein the second file remains in the first tier storage region and is not migrated to the second tier storage region, wherein the first tier storage region corresponds to a first logical volume and contains the first storage address, and the second tier storage region corresponds to a second logical volume and contains the second storage address; wherein both the first tier storage region and the second tier storage region are mapped to a virtual volume according to a virtual volume manager and wherein copying the data from the first tier storage region to the second tier storage region is performed according to a data migration program of the storage controller; and wherein the first logical volume is defined by the one or more first tier physical storage devices, and the second logical volume is defined by the one or more second tier physical storage devices, the virtual volume comprising an address space independent of address spaces of the first or second logical volumes, wherein contiguous ranges of the address space of the virtual volume each maps to an address space of one of the first or second logical volumes, and wherein a mapping is maintained of data blocks in the address space of the virtual volume to the address space of the logical volumes.