Patent ID: 7757038
Filing Date: 2010-07-13
Classification: G06F,G11C

Abstract:
1. A storage device comprising: a RAID controller unit controlling a read request and a write request from a host unit; and a storage unit having a plurality of flash drives each flash drive comprising a drive controller and a plurality of flash memory devices in which a functional capacity unit is smaller than an entire capacity of the flash memory devices, wherein the drive controller of each flash drive determines a writing lifetime for each functional capacity unit in the flash drive, wherein the drive controller of a first flash drive upon determining at least one functional capacity unit of the flash memory devices in which the writing lifetime exceeds a predetermined value, replaces the at least one functional capacity unit by a functional capacity unit of flash memory devices of a second flash drive, and wherein, if the data of the at least one functional capacity unit has not been updated, the drive controller of the first flash drive controls to read data of the at least one functional capacity unit from the flash memory devices of the first flash drive in response to a read request from the host unit, and wherein the drive controller of the second flash drive controls to write data of the at least one functional capacity unit to the flash memory devices of the second flash drive in response to a write request from the host unit.