Multiple disk data storage system for reducing power consumption

Abstract

A disk controller connected to a set of disks in a data storage system is configured to mirror a first class of data on multiple disks while storing a second class of data without mirroring. The controller maintains at least one of the disks containing the first class of data in an operational state while maintaining at least one of the remaining disks in a low power state. The first class of data may contain popular files while the second class of data contains unpopular files. The first data class may be mirrored on each of the disks. The data in the second class may be stored with parity where the parity information is maintained on a single disk. The operational disk may be changed following access to data from the second class of data that is stored on one of the low power state disks.

Dependencies are inferred from the claim text.