STORAGE DEVICE INCLUDING A RAID1-TYPE RAID GROUP, AND WRITING CONTROL METHOD TO RAID1-TYPE RAID GROUP

摘要

A RAID1-type RAID group has more than one pair of a first-memory device and a second-memory device. A storage device reads data from all regions of a first-storage block that includes a writing destination of data targeted for writing, in a first-memory device. The storage device has more than one data unit which is data of a same size as a first-memory block, composed of data targeted for writing or a copy thereof and a staging data portion or a copy thereof, based on data targeted for writing and staging data which is data to be read. A controller writes either of one or more of a data unit to the first-storage block of the first-memory device, and one or more of a data unit to a second storage block that is a same size corresponding to the first-storage block in a second-memory device.