Storage control device

Abstract

The storage control device of the present invention reduces power consumption by stopping the flow of power to enclosures that are not being accessed. A plurality of additional enclosures are connected to a base enclosure by means of a daisy-chain connection. The respective additional enclosures are divided into three levels, namely a low usage frequency level, a medium usage frequency level, and a high usage frequency level depending on the connection distance of the additional enclosures from the base enclosure. Drives that have not been accessed for a predetermined time are spun down. When all the drives in the enclosure are in the spindown state, the supply of power from the power supply to the respective drives is stopped. Further, when the flow of power to an additional enclosure located below the enclosure itself has stopped, the switch of the latter enclosure is turned OFF and the flow of power to the additional enclosure is stopped.

1 . A storage system comprising;
 a first enclosure, which is coupled to a host computer, including a first controller controlling access command from the host computer;   a second enclosure, which is coupled to the first enclosure, including a plurality of first storage devices;   a third enclosure, which is coupled to the second enclosure, including a plurality of second storage devices;   wherein the first controller issues a first instruction to the third enclosure to shift (or change) state of a storage device which is included in the second storage devices to a power save state, the storage device has not been accessed for a time or more,   wherein if states of the second storage devices are the power save state, the first controller controls to stop power supply to the third enclosure.   
   
   
       2 . A storage system according to  claim 1 ,
 wherein the second enclosure includes a second controller,   wherein the third enclosure includes a third controller,   wherein if the third enclosure receives the first instruction from the controller, the third controller controls to shift (or change) the state of the storage device to the power save state.   
   
   
       3 . A storage system according to  claim 2 ,
 wherein the third enclosure further includes a cooling fan,   wherein if the third controller controls shift (or change) the state of the storage device to the power save state, the third controller controls to reduce rotational speed of the cooling fun.   
   
   
       4 . A storage system according to  claim 1 , further comprising:
 a power distribution circuit, which is coupled to a power supply, including a first switch coupled to the first enclosure, and a second switch coupled to the second enclosure, and a third switch coupled to the third enclosure.   
   
   
       5 . A storage system according to  claim 4 ,
 wherein when the first controller controls to stop power supply to the third enclosure, the controller controls to turn off the third switch included in the power distribution circuit.   
   
   
       6 . A storage system according to  claim 5 ,
 wherein the first storage devices in the second enclosure forms a plurality of logical volumes,   wherein the first controller detects usage states of the logical volumes in the second enclosure,   wherein if a usage state of a logical volume included in the logical volumes is lower than a predetermined value, the first controller controls to migrate a data stored in the logical volume in the second enclosure to the third enclosure.   
   
   
       7 . A storage system according to  claim 6 ,
 wherein the first storage devices in the second enclosure has higher performance than the second storage devices.   
   
   
       8 . A storage system according to  claim 7 ,
 wherein the first storage devices are Fiber Channel disk drives,   wherein the second storage devices are Serial At Attachment disk drives.   
   
   
       9 . A storage system according to  claim 1   wherein the first controller issues a second instruction to the second enclosure to shift (or change) state of a storage device which is included in the first storage devices to the power save state, the storage device has not been accessed for a time or more,   wherein if states of the first storage devices are the power save state, the first controller controls to stop power supply to the second enclosure.   
   
   
       10 . A storage system comprising;
 a first enclosure, which is coupled to a host computer, including a controller controlling access command from the host computer;   a second enclosure, which is coupled to the first enclosure, including a plurality of storage devices;   wherein the controller issues an instruction to the second enclosure to shift (or change) state of a storage device which is included in the storage devices to a power save state, the storage device has not been accessed for a time or more,   wherein if states of the second storage devices are the power save state, the controller controls to stop power supply to the third enclosure.   
   
   
       11 . A storage system comprising;
 a first enclosure, which is coupled to a host computer, including a first controller controlling access command from the host computer;   a second enclosure, which is coupled to the first enclosure, including a plurality of first storage devices;   a third enclosure, which is coupled to the second enclosure, including a plurality of second storage devices;   wherein the first controller issues an instruction to the third enclosure to shift (or change) state of a storage device which is included in the second storage devices to a power save state,   wherein if states of the second storage devices are the power save state, the first controller controls to stop power supply to the third enclosure.   
   
   
       12 . A storage system according to  claim 11 ,
 wherein the second enclosure includes a second controller,   wherein the third enclosure includes a third controller,   wherein if the third enclosure receives the first instruction from the first controller, the third controller controls to shift (or change) the state of the storage device to the power save state.   
   
   
       13 . A storage system according to  claim 11 , further comprising:
 a power distribution circuit, which is coupled to a power supply, including a first switch coupled to the first enclosure, and a second switch coupled to the second enclosure, and a third switch coupled to the third enclosure.   
   
   
       14 . A storage system according to  claim 13 ,
 wherein when the first controller controls to stop power supply to the third enclosure, the controller controls to turn off the third switch included in the power distribution circuit.