Power management for a data storage system

Abstract

A data storage system includes a plurality of storage devices that are each configured to store host data from a host and to be in a first operating mode or a second operating mode. The second operating mode is a reduced power mode relative to the first operating mode. A bridge of the data storage system is configured to indicate to the host that the plurality of storage devices is in the first operating mode when one or more of the plurality of storage devices is in the second operating mode.

What is claimed is: 
     
         1 . A data storage system comprising:
 a plurality of storage devices, each storage device of the plurality of storage devices configured to store host data from a host and further configured to be in a first operating mode or a second operating mode, wherein the second operating mode comprises a reduced power mode relative to the first operating mode; and   a bridge configured to be connected to the host and the plurality of storage devices, wherein the bridge is further configured to indicate to the host that the plurality of storage devices is in the first operating mode when one or more of the plurality of storage devices are in the second operating mode.   
     
     
         2 . The data storage system of  claim 1 , wherein the bridge is further configured to indicate to the host that the plurality of storage devices is in the first operating mode when all of the plurality of storage devices are in the second operating mode. 
     
     
         3 . The data storage system of  claim 1 , wherein the plurality of storage devices comprise at least one hard disk drive and at least one solid state drive. 
     
     
         4 . The data storage system of  claim 1 , wherein the first operating mode comprises an active mode and the second operating mode comprises a slumber mode. 
     
     
         5 . The data storage system of  claim 1 , wherein the bridge comprises a Serial Advanced Technology Attachment (“SATA”) to dual SATA bridge. 
     
     
         6 . The data storage system of  claim 1 , wherein the data storage system and the host form a computer system. 
     
     
         7 . The data storage system of  claim 1 , wherein the host is configured to transmit the host data to the plurality of storage devices when the bridge indicates to the host that the plurality of storage devices is in the first operating mode. 
     
     
         8 . The data storage system of  claim 1 , wherein the bridge is further configured to:
 receive a host command for the data storage system to enter the first mode; and   prevent the host command from reaching the plurality of storage devices.   
     
     
         9 . The data storage system of  claim 8 , wherein the host command is a Host Initiated Power Management (HIPM) command. 
     
     
         10 . The data storage system of  claim 1 , wherein the bridge is further configured to provide power management for each of the storage devices of the plurality of storage devices using Device Initiated Power Management (DIPM) at the bridge. 
     
     
         11 . The data storage system of  claim 1 , wherein the bridge is further configured to use DIPM to indicate to the host that the plurality of storage devices is in the first operating mode. 
     
     
         12 . The data storage system of  claim 1 , wherein at least one storage device of the plurality of storage devices is a cache memory of another storage device in the plurality of storage devices. 
     
     
         13 . A method for operating a data storage system including a plurality of storage devices, the method comprising:
 indicating to a host using a bridge in the data storage system that the plurality of storage devices is in a first operating mode when one or more of the plurality of storage devices are in a second operating mode,   wherein each of the plurality of storage devices is configured to store host data from the host and be in the first operating mode or the second operating mode, and   wherein the second operating mode comprises a reduced power mode relative to the first operating mode.   
     
     
         14 . The method of  claim 13 , further comprising indicating to the host using the bridge that the plurality of storage devices is in the first operating mode when all of the storage devices of the plurality of storage devices are in the second operating mode. 
     
     
         15 . The method of  claim 13 , wherein the first operating mode comprises an active mode and the second operating mode comprises a slumber mode. 
     
     
         16 . The method of  claim 13 , further comprising transmitting the host data by the host to the plurality of storage devices when the bridge indicates to the host that the plurality of storage devices is in the first operating mode. 
     
     
         17 . The method of  claim 13 , further comprising:
 receiving a host command at the bridge for the data storage system to enter the first mode; and   preventing the host command from reaching the plurality of storage devices.   
     
     
         18 . The method of  claim 18 , wherein the host command is a Host Initiated Power Management (HIPM) command. 
     
     
         19 . The method of  claim 13 , further comprising using the bridge to provide power management for each of the storage devices in the plurality of storage devices with Device Initiated Power Management (DIPM) at the bridge. 
     
     
         20 . The method of  claim 13 , further comprising using DIPM to indicate to the host that the plurality of storage devices is in the first operating mode. 
     
     
         21 . The method of  claim 13 , wherein at least one of the plurality of storage devices is a cache memory of another storage device in the plurality of storage devices.