Disk array system

In the disk array system, in the basic chassis, HDD modules are installed from a front surface in a front part of a backboard, and duplex CTL modules are installed up and down from a rear surface in a rear part, and duplex power source modules containing fans are installed in the left and right sides thereof. By the operation of the fans, in the rear part, the cooling air flows separately into each CTL module and into each power source module, and the cooling air having passed through the area of the duct by a block in the CTL module is drawn by the fans in the power source module through a ventilation hole and is then exhausted outside. The cooling air flow path to the plurality of ICs is divided by the block. The rotation speed of the fans is controlled by using a temperature sensor.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese Patent Application No. JP 2007-88552 filed on Mar. 29, 2007, the content of which is hereby incorporated by reference into this application.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a disk array system (also referred to as a storage system) having a function to control a storage device such as a HDD (Hard Disk Drive). More particularly, it relates to configurations of a system chassis and various modules installed therein and ventilation and cooling structures of the system chassis and the modules.

BACKGROUND OF THE INVENTION

In a recent disk array system, mounting density has been increased and performance thereof has been improved. Accordingly, higher cooling performance has also been demanded in order to cope with the temperature rise due to the increase in heat generation of component parts and resulting performance deterioration.

For example, in the disk array system of a predetermined method, elements such as boards (circuit boards) corresponding to various functions and power sources are installed in the system chassis by means of the structure and method of a module (also referred to as a unit, package, and assembly) to take the maintainability into consideration. Further, by mounting fans, heat sinks and others in the system chassis and modules, considerations are given to the ventilation and cooling function. For example, the high-density mounting and high cooling performance are realized by the configuration in which each module is inserted through the opening in front or at the back of the chassis and connected to the front or rear surface of a backboard inside the chassis and by the configuration in which a cooling air flows to the rear surface (back side) from the front surface of the chassis via the backboard by the fan operation.

For example, Japanese Patent Application Laid-Open Publication No. 2004-022057 (Patent Document 1) discloses an example of the configuration of the conventional disk array system.

SUMMARY OF THE INVENTION

With respect to the configurations of the chassis and the module in the conventional disk array system, it is necessary to realize a configuration more effective than the conventional one in consideration of high density mounting and cooling performance. In particular, a disk array system that can satisfy needs of an end user such as the size reduction and higher cooling performance has been demanded.

The present invention has been made in view of the above described problems, and an object of the present invention is to provide a technology that can realize an effective structure with respect to the configurations of the chassis, module, and the like and the ventilation and cooling structures in the disk array system in which high density mounting and cooling performance are taken into consideration.

The typical ones of the inventions disclosed in this application will be briefly described as follows. In order to achieve the above described object, the present invention provides a disk array system comprising a group of storage devices (disk array) such as a HDD and a control device thereof (controller or disk controller), wherein elements such as controllers and power sources are installed in the system chassis by means of the structure and method of a module, and in a redundant configuration in which each function is at least duplicated, each module is inserted through the opening in front or at the back of the chassis and connected to the front or rear surface of a backboard inside the chassis, and cooling is performed by the air ventilated to the rear surface (back side) from the front surface of the chassis via the backboard by the fan operation, and wherein technological means and configurations as shown below are provided.

In the disk array system of the present invention, in consideration of the high density mounting and cooling performance, new configurations for the chassis, modules and others and new cooling structure are provided. The feature of this system lies in that the types of modules and the layout thereof in the chassis are reviewed and the types of modules to be used are reduced, thereby reducing the size of the system. In the configuration of a basic chassis, a storage device module (for example, the SAS HDD) and others are installed from the front surface in the front part partitioned by the backboard, and duplex (two) controller modules are installed up and down from the rear surface in the rear part, and in the left and right areas thereof, duplex (two) power source modules containing a fan unit (a plurality of fans) are installed. In the rear part, the two types of modules (four modules in total) are mainly installed. Further, in the configuration of an expanded chassis, an enclosure module is installed in place of the controller module. The fan unit in the power source models comprises, for example, duplex fans installed front and back, and up and down.

A HDD connecter is disposed near the longitudinal center of the backboard so as to correspond to the position of a connector of the SAS HDD, and a connector of the controller is disposed near the upper and lower edges of the backboard so as not to interfere with that connector. Further, two power source modules are disposed in the left and right areas of the two controller modules so as to correspond to positions of the left and right edges of the backboard.

Also, a cooling air flow path in the configuration of the chassis and modules is devised. By the operation of the fan in the power source model, cooling air is taken from the front surface of the chassis to cool the storage device module and others, and then, it flows into the rear part through the opening holes of the backboard. For example, in the front part, the group of storage device modules disposed on the upper side is cooled by the cooling air much more than battery modules and others disposed on the lower side. Also, when the cooling air flows into the rear part, the cooling is split, and one (first cooling air) flows into each controller module and the other (second cooling air) flows into each power source module through the opening holes of the backboard. An almost equal amount of the cooling air is supplied to the duplex modules. In the rear part, inside of each power source module (power source unit) and controller module (components on a substrate such as IC and others) are cooled by the cooling air.

In the power source module, the cooling air (second cooling air) passes through the power source unit on the side close to the connecter and is drawn by the fan unit disposed close to the front surface side of the power source module (rear surface side of chassis) at the back of the power source. In the controller module, the cooling air (first cooling air) passes through the area of a duct structure formed by the disposed blocks and cools objects to be cooled such as IC and others on the substrate. The cooling air is not exhausted from the front surface side (rear surface side of chassis) of the controller module to the outside, but it is drawn by the fan units (fan) in the left and right power source modules through a ventilation hole area at a position close to the rear surface of the chassis in a first partition plate (and side surfaces of corresponding modules) between the controller module and the power source module. Then, the cooling air from the controller side together with the cooling air (second cooling air) from the power source side are exhausted outside through the exhaust port of the fan and exhaust hole on rear surface side of the chassis. In this manner, the cooling structure of the area combined with the power source module and the controller module is made more efficient.

Further, this system gives special consideration to the efficient cooling of components (cooling object components) disposed on the cooling air flow path on the substrate in the controller module, in particular, components such as a plurality of ICs adjacently disposed in a row in a back-and-forth direction of the chassis and heat sinks disposed thereon. As the means for this purpose, an effective cooling air flow path (duct structure) that passes through the area of the cooling object components on the substrate is formed by a block structure for the cooling object components. For example, the block is designed to have a roughly trapezoidal shape in section in the back-and-forth direction of the chassis so as to have a slope (inclination) by a side of the trapezoid in the vicinity of the inflow of the cooling air toward the area of the cooling object components. By this means, the flowing cooling air can be smoothly applied to the cooling object components.

Further, in particular, by means of the change in layout and shape of the block, for example, by providing holes and concavity and convexity, the cooling air flow path to the area of the cooling object components is branched so as to correspond to a plurality of cooling object components on the substrate. By this branching, the cooling air can be directly applied to not only the components at a former stage close to the backboard and connector side but also the components at a latter stage of the plurality of cooling object components, and the cooling performance can be improved.

Further, in the controller, enclosure, and others, based on the temperature detected by a temperature sensor provided in the chassis, the rotation speed of the fans in the power source modules are controlled. For example, when the detected temperature reaches the predetermined value or more, the rotation speed of the fans are increased.

The effects obtained by typical aspects of the present invention will be briefly described below. According to the present invention, it is possible to realize an effective structure with respect to the configurations of the chassis, module, and the like and the ventilation and cooling structures in the disk array system in which high density mounting and cooling performance are taken into consideration.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

Characteristics of Embodiment

A disk array system according to an embodiment of the present invention will be described with reference toFIG. 1toFIG. 20. The main characteristics of the present embodiment are as follows (seeFIG. 10and others). In a disk array system5, for example, in a basic chassis100, HDD modules30and others are installed in a front part1partitioned by a backboard20from a front surface (A), and duplex CTL modules10are installed up and down in a rear part2from a rear surface (B), and further, duplex power source modules40containing a plurality of fans43are installed in the left and right areas thereof. By the operation of the fans43, the cooling air flows from the front surface (A) to cool the HDD modules30and others, and it flows into the rear part2through opening holes220of the backboard20. Then, in the rear part2, one cooling air flows into each CTL module10, and the other cooling air flows into each power source module40. In the CTL module10, the cooling air passes through an area114with a duct structure by a block150and cools cooling object components such as ICs. The cooling air is not exhausted from the CTL module10, but is drawn by the fans43in the power source module40through a ventilation hole96and the like of a partition plate95, and then exhausted to the outside together with the cooling air in the power source module40. By branching the cooling air flow path to a plurality of components such as ICs on a CTL substrate120by changing the structure of the block150, the cooling air is directly applied also to the components of the latter stage. Further, the rotation speed of the fans43is controlled by the CTL110and others based on the temperature detected by a temperature sensor115.

FIG. 1shows the functional block configuration of an information processing system in this disk array system5. A host system7is a high order information processing system such as a PC, a server, and a main frame used by a user. The host system7and the disk array system5are connected by communication means such as a SAN (Storage Area Network)6or a LAN (Local Area Network).

The disk array system5mainly comprises a basic chassis100and an expanded chassis200. The basic chassis100is provided with both a control function (CTL110and the like) and a storage function (HDD31group). The expanded chassis200is optional and is mainly provided with the storage function (HDD31group).

A controller (CTL#1and #2)110comprises a CPU11, a bridge12, a program memory (P memory)13, a host I/F (also referred to as a host-interface control unit, a channel I/F control unit, and the like)14, a data controller (DCTL)15, a disk I/F (disk interface control unit)16, a cash memory (CM)17, a switch (SW)18, and others.

The CPU11executes a program stored in the program memory13through the bridge12, thereby performing a processing to control the entire system. The DCTL15mutually connects each of the units and controls data transmission. The cache memory CM17is a shared memory to cash (store) the data in the CTL110. The host I/F14is a processing unit to which the host system7and the like are connected. The disk I/F16is a processing unit to which the HDD31group is connected via the SW18.

The SW18has a SAS expander (EXP) function and an environment management function. The EXP function is a function such as an access control for the group of HDDs31corresponding to the SAS interface. The environment management function includes a function (conventional environment management function) to monitor and detect a trouble, a failure and a state such as connection regarding resources such as a power source (PS), fans, and the HDD31and a temperature management function (cooling management function) including a fan control which is one of the characteristics of the present invention to be described later.

The HDD31is a HDD with the SAS interface (or SATA interface). On the physical memory area provided by the HDD31group, a logical volume which is a logical memory area is set. Further, a RAID group by the plurality of HDDs31is set, and a RAID control can be executed. The SAS HDDs31are connected by “two-path two-port” to the SW18and a SW19.

The enclosure (ENC#1and #2)170comprises the SW19and performs a connection with the CTL110and a relay to the ENC170when another ENC170is connected. The SW19has a function similar to that of the SW18in the CTL110of the basic chassis100, and it takes charge of the control inside the expanded chassis200. The SW18of the basic chassis100and the SW19of the expanded chassis200are connected, and the disk I/F16can access the target HDDs31in the basic chassis100and the expanded chassis200.

As shown by a chain line in the center, the CTL110, ENC170, HDD31group, and others are duplicated, and an access can be made from one side (#1and #2) to the other side (#2and #1).

The data processing in the disk array system5is as follows. In response to a data write request (command) from the host system7, the CTL110temporarily stores the data received from the host I/F14in the CM17and writes the data in the predetermined logical volume on the HDD31group by the disk I/F16. Further, in response to the data read request (command) from the host system7, the CTL110reads the data from the predetermined logical volume on the HDD31group by the disk I/F16and stores the data temporarily in the CM17, and then transmits it to the host system7through the host I/F14. Since a plurality of host I/Fs14and a plurality of disk I/Fs16are provided in this configuration, a plurality of data inputs and outputs can be processed in parallel.

FIG. 2shows a system configuration (duplicated parts are omitted) for connecting the modules (shown by m) to the backboards (BB)20and20B in the basic chassis100and the expanded chassis200of the disk array system5. Through the wirings of the backboard20and20B, each of the components is mutually connected. In the basic chassis100, the HDDs31of the plurality of HDD modules30, duplex battery modules50, and a panel module60are connected to the front surface of the backboard20through the connectors. Further, the duplex CTL modules10and the duplex power source (PS) modules40are connected to the rear surface of the backboard20. In the expanded chassis200, the HDDs31of the plurality of HDD modules30are connected to the front surface of the backboard20B through the connectors. Further, the duplex ENC modules70and duplex power source modules80are connected to the rear surface of the backboard20B.

The SW18of the CTL110(the bridge12and others are omitted here) and the SW19of the ENC170have the SAS expander (EXP)21corresponding to the EXP function and the environment management unit (K)22corresponding to the environment management function. Between the chassis, the connection between the EXPs21is made by a communication cable and the like. Incidentally, the configuration in which the environment management unit (K)22is located at positions other than the SW18and SW19is also possible.

The EXP21, based on a control from the high order disk I/F16, controls data input and output accesses and the path switching and others to the HDD31group of each chassis by the SAS interface.

The environment management unit (K)22, based on a control from the high order (CPU11and others), monitors and detects a state of the power source unit (41and the like), fan unit (42and the like), the HDD31and the like installed in the chassis and performs the control of the power source system and the control of the fan operation mode (fan control and cooling system control) using the fan unit (42and the like) through the backboard20and others.

The power source module40comprises a power source unit41and a fan unit42. The power source unit41, based on an AC input, converts AC into DC by an AC/DC conversion unit411and outputs DC power to the backboard20from a DC output unit412. The DC power is supplied to each component through the circuit of the backboard20. The AC/DC conversion unit411corresponds to an SWPS913. The fan unit42comprises a plurality of fans43. The DC power (driving voltage) is inputted to the fan unit42from the power source41and others and the fans43are rotated. The rotation speed of the fan43is controlled by the driving voltage.

The power source module80on the expanded chassis200side has basically the same configuration (layout, cooling structure and the like are different) as the power source module40on the basic chassis100side, and it comprises a power source unit81, a fan unit82(a plurality of fans83) and others.

The configuration of the power source system of the disk array system5will be described with reference toFIG. 3. This is the configuration of the power source of two systems corresponding to the duplex structures such as the CTL110, ENC170, and HDD31group. The power source unit41(#1and #2) in each power source module40(or80) has a redundant configuration comprising two switching power sources (SWPS)913(corresponding to411). This power source unit41generates DC outputs (DC#1and #2) based on two AC inputs (AC#1and #2), respectively, and outputs them to each component of the corresponding CTL110and the like.

In each CTL110, each processor911(CPU11and the like) can refer not only to the memory912(CM17and the like) on its own side (for example, #1) but also to the processor911and the memory912in the CTL110of the other side (for example, #2). The read/write of the data, the control information and others can be mutually performed between the duplex CTLs110so that no problem occurs even when one of them is in trouble.

The DC output is supplied also to components such as the ENC170, HDDs31, and the like from the corresponding power source unit in the same manner. When the DC supply is cut off, the DC output is supplied from the battery module50.

The battery module50corresponds to UPS (uninterruptible power source unit), and it contains a plurality of batteries and supplies an emergency power source. When the power supply is stopped due to the power outage and the like, the battery module50supplies necessary power to prevent the data loss and the like at the power outage. More specifically, the battery module50supplies at least the power required until the data of the memory912(CM17and the like) is written in the HDD31by the processor911of the CTL110and a premeditated stop is automatically executed and completed. As a result, the data loss at the time of the power outage can be prevented.

Next, the external configuration of the entire hardware of the chassis of the disk array system5will be described with reference toFIG. 4toFIG. 9and others. The basic chassis100and the expanded chassis200have a predetermined size which is mountable on a rack (frame) with a size in conformity to the predetermined standard. The size of the basic chassis100is Width: X1, Depth: Y1, and Height: Z1. The size of the expanded chassis200is Width: X1, Depth: Y1, and Height: Z2. Specifically, as the size of the height of the chassis, 3U (approximately 133.35 mm), 4U, and others in EIA STANDARD EIA-310-D are suitable. A ratio of the height (Z1) of the basic chassis100and the height (Z2) of the expanded chassis200is preferably 4U:3U. For example, the rack (not shown) has a box shape with openings in its front and rear surfaces, and each chassis (100and200) can be mounted up and down therein.

The modules to be installed in each of the chassis include various types modules in the present embodiment, for example, the CTL module10, the HDD module30, the power source module40, the battery module50, the panel module60, the ENC module70, and the power source module80. In the installation of the HDD module30to the chassis, the hot plug is enabled. Operations such as insertion/removal and fixation of each module to and from the chassis (100and200) by a person are performed by using an operating lever and the like provided in the module. The operation of the HDD module30is performed by using the operating handle and the like.

The operation in the case of the modules (CTL module10, power source module40, battery module50, ENC module70, and power source module80in the present embodiment) provided with the operating lever is as follows. First, when mounting the module in the chassis, a customer engineer or end user inserts the module into a predetermined area in the chassis, connects the connector thereof to the backboard20, and then moves down the operating lever to fix the module (fixed state) by a latch action. When taking out the module from the chassis, the customer engineer or end user moves up the operating lever to release the fixed state by a latch release action and removes the module from the predetermined area in the chassis.

Each chassis is made of metal in general and has a box shape, and can be disassembled by screws and others. A partition plate and the like which correspond to the area to which each module is installed are provided in the chassis. Further, an outer wall (main body) and the partition plate of the chassis are provided with the structure corresponding to the operation of insertion/removal and fixation of the modules, for example, a guide rail (structure of grooves, protrusions, and the like) and a receiving portion of the operating lever (structure for receiving a latch portion and a hook portion of the operating lever). Further, the partition plate (and its ventilation holes and the like) has a function to adjust the flow of the cooling air in addition to the function of fixation, reinforcement, and the like. Incidentally, the duplex two modules have the same configuration and are configured to be attachable to both of the two mounting areas in the chassis.

A hardware configuration of the basic chassis100will be described with reference toFIG. 4andFIG. 5.FIG. 4is a diagram showing the configuration seen from the side of the opening of the front surface (A) of the basic chassis100, andFIG. 5is a diagram seen from the side of the opening of the rear surface (B) of the basic chassis100.

InFIG. 4, the basic chassis100has openings in the front surface (A) and the rear surface (B) thereof, and the chassis is divided into a front part1(front surface side space) and a rear part2(rear surface side space) by the backboard20attached to the position at the midpoint in the chassis as a boundary.

In the front surface (A) of the front part1of the basic chassis100, a plurality of HDD modules30can be attached to the upper side thereof. Further, two battery modules50and the panel module60can be attached to the lower side thereof. A bezel (door)91having an air permeability can be attached to the front surface (A) in a state where each module is installed.

InFIG. 5, the rear surface (B) of the rear part2of the basic chassis100has the configuration to which two CTL modules10and two power source modules40can be mounted. Two power source modules40are installed on the left and right sides of the rear surface (B) of the rear part2, and two CTL modules10are installed in the area sandwiched between these modules.

A hardware configuration of the expanded chassis200will be described with reference toFIG. 6andFIG. 7.FIG. 6shows a configuration of the expanded chassis200seen from the side of the opening of the front surface (C), andFIG. 7shows a configuration of the expanded chassis200seen from the side of the opening of the rear surface (D).

InFIG. 6, the expanded chassis200has the openings in the front surface (C) and the rear surface (D) thereof, and the chassis is divided into a front part3(front surface side space) and a rear part4(rear surface side space) by the backboard20B attached to the position at the midpoint in the chassis as a boundary.

In the front surface (C) of the rear part3of the expanded chassis200, the plurality (15 sets) of HDD modules30can be attached in a state aligned in a lateral direction. Incidentally, in the case of the expanded chassis200, other modules do not have to be installed on the front surface (C) side.

InFIG. 7, the rear surface (D) of the rear part4of the expanded chassis200has the configuration to which two ENC modules70and two power source modules80can be mounted. The duplex ENC modules70are disposed side by side in an upper central area of the rear surface (D) of the rear part4, and the duplex power source models80are disposed side by side in an area below them.

Next,FIG. 8Ashows a configuration of the front surface (A) of the basic chassis100. In the front part1, a plurality (up to 15 sets in the present embodiment) of HDD modules30in an upright position are installed in a relatively wider upper area (A1) in a state aligned in a lateral direction. Two battery modules (#1and #2)50in a horizontal position are installed side by side in a relatively narrower lower area (A2), and the panel module60is installed adjacent to the battery module, that is, in the lower right corner area of the front surface (A). The panel module60is a unit to display basic operations and states such as ON and OFF of the power source in the system. The boundary between the upper area (A1) and the lower area (A2) is provided with a partition plate. The operating lever is provided at one position of the lower side of the battery module50.

FIG. 8Bshows a configuration of the rear surface (B) of the basic chassis100. In the rear part2, the power source modules (#1and #2)40in an upright position are installed in the areas (B2) close to the left and right sides of the rear surface (B). Two CTL modules (#1and #2)10in a horizontal position are installed up and down in the intermediate area (B1) sandwiched between the power source modules. The same two CTL modules10are installed upside down relative to each other. The same two power source modules40laterally reversed to each other are installed.

The partition plate95is provided at the boundary between the side surface of the power source module40and the side surface of the CTL module10. A partition plate is provided at the boundary between the upper and lower two CTL modules10.

A surface of a host I/F unit103corresponding to the host I/F14and an area107of various types of terminals are provided in a part of the front surface (106) of the CTL module10. Two operating levers104are provided at the left and right corners of the front surface of the CTL module10, and the insertion/removal and the fixation of the CTL module10by the two operating levers104can be performed.

An exhaust hole48and the like corresponding to the positions of the exhaust ports of a power source switch and a fan43are provided in the front surface of the power source module40. One operating lever46is provided on one side surface of the power source module40.

FIG. 9Ashows a configuration of the front surface (C) of the expanded chassis200. A plurality (up to 15 sets) of HDD modules30are installed into the entire area of the front part31in a state aligned in a lateral direction.

FIG. 9Bshows a configuration of the rear surface (D) of the expanded chassis200. In the rear part4, two ENC modules70in a horizontal position are installed side by side in an upper central area (D1) of the rear surface (D). Two power source modules80in a horizontal position are installed side by side in the lower area (D2). The two ENC modules70and the two power source modules80are oriented in the same direction.

The partition plate97is provided at the boundary between the upper ENC module70and the lower power source module80. A partition plate is provided between the left and right modules. One operating lever is provided at the middle of the front surface of the ENC module70.

The ventilation hole and the like corresponding to the positions of the exhaust ports of a power source switch and a fan (83) are provided in the front surface of the power source module80. Two operating levers are provided at the upper left and right sides of the power source module80.

Next,FIG. 10shows a schematic horizontal planar configuration (corresponding to the section of one CTL module10seen from above) of the basic chassis100. Further, the arrow marks show representative flow and a flow amount of the cooling air (to be described later). The front part1has the HDD modules30, and the rear part2has the CTL module (#1)10and the two left and right power source modules40. Two fans43as a fan unit42are provided in a row in a back-and-forth direction on the rear side of the power source module40. Ventilation holes96are provided at the illustrated positions in each partition plate95between the CTL module10and the power source module40. An area114in which a block150is disposed above such components as ICs on the substrate is provided in the CTL module10.

FIG. 11shows a schematic vertical planar configuration (corresponding to the section of the CTL module10seen from the side thereof) of the basic chassis100. In the front part1, the HDD module30is installed on the upper side, and the battery module50is installed on the lower side. In the rear part2, two CTL modules10are installed up and down. The block150is provided on the front side in the CTL module10. A ventilation hole105is provided on the rear side of the side surface of the CTL module10.

FIG. 12shows the surface (front surface) of the backboard20in the basic chassis100. The backboard20is a circuit board with a roughly flat planar shape and is fixed to a frame part positioned at the middle and slightly close to the front side of the basic chassis100. The backboard20electrically connects each of the modules by connector connection and physically supports them. The fixation of the module mentioned here corresponds to the state in which the connector of the rear surface of the module and the corresponding connector of the backboard20are engaged and electrically connected.

A group of connectors (203,205, and206) for connecting the HDD module30, the battery module50, the panel module60, and the like are provided on the front surface of the backboard20. A group of connectors (201and204) for connecting the CTL module10, the power source module40, and the like are provided on the rear surface of the backboard20. Further, wiring patterns for the mutual connection between the connectors and openings (ventilation holes)220through which the cooling air is supplied from the front part1to the rear part2are provided in the backboard20.

A plurality of connectors (HDD connectors)203for the connection of the HDD modules30with a longitudinal rectangular shape are disposed on a zone extending in a lateral direction near the center (center zone) of the backboard20. Further, connectors (battery connectors)205for the connection of the battery modules50with a horizontal rectangular shape are disposed below the HDD connectors203. Further, a connector (panel connector)206for the connection of the panel module60is disposed near the lower right corner of the backboard20.

Further, connectors (CTL connectors)201to be connected to the CTL modules10are disposed near the center of the upper and lower sides on the rear surface side of the backboard20, while interposing the area of the HDD connector203therebetween. That is, on the upper side, the CTL connector201for the connection of the module (10) of a first CTL (#1) with a lateral rectangular shape is disposed. On the lower side, the CTL connector201for the connection of the module (10) of a second CTL (#2) is similarly disposed. Further, connectors (power source connectors)204for the connection of each power source module40with a longitudinal rectangular shape are disposed near the center of the left and right sides of the backboard20.

Further, in the center zone of the backboard20, a plurality of opening holes220with a longitudinal rectangular shape are formed between the HDD connectors203. In addition, opening holes220with a lateral rectangular shape are formed on both sides of the upper CTL connector201. The position, shape, size, and the like of the opening holes220are designed based on the flow amount distribution of the cooling air flow path in the chassis (to be described later).

Next,FIG. 13AandFIG. 13Bshow the HDD module30(also referred to as canister module). The HDD31is stored in the HDD module30, and a connector32to be connected to the connector203on the backboard20is provided on the rear surface of the HDD module30. A handle301is provided on the front surface of the HDD module30, and the operation of insertion/removal and fixation of the HDD module30can be performed by this handle. The HDD module30has a uniform external appearance by the design of the handle301and the like. The HDD31of the HDD module30installable in the present embodiment is either the Serial Attached SCSI HDD (SAS-HDD)31shown inFIG. 13Aor the Serial ATA (SATA) interface HDD (SATA-HDD)35shown inFIG. 13B.

InFIG. 13A, in consideration of the position of the connector32of the SAS-HDD31and the installing position of the HDD module30, the connector position of each of other modules, the module installing position, and shape are designed. Between the duplex CTL110(disk I/F16) and the SAS-HDD31, the data input/output processing is performed by the “two-port and two-path (2P)” according to the SAS interface. The SAS-HDD31side has two ports (2P).

InFIG. 13B, when the HDD module30of the SATA-HDD35is installed, a path control board (I/F conversion substrate)37is interposed and connected between the connector36of the SATA-HDD35and the connector (203) of the backboard20so as to match with the position of the connector32of the SAS-HDD31. More specifically, the connector32of the SAS-HDD31and the corresponding connector of the path control board37are connected, and the connector38of the path control board37and the corresponding connector (203) of the backboard20are connected. The SATA-HDD35has one port (1P). In the case of the connection of the SATA-HDD35, the I/F conversion is performed by the SATA and the SAS by the control board37having the two ports.

InFIG. 14AandFIG. 14B, the power source module40has an integrated module configuration including the power source unit41and the fan unit42, thereby reducing the size of the chassis.FIG. 14Ashows a state in which one power source module40is installed between the outer wall99of the basic chassis100and the partition plate95in a horizontal plane.FIG. 14Bschematically shows the state in a vertical plane (side surface).

The power source unit41comprises a substrate44, and a connector45to be connected with the corresponding connector204of the backboard20is provided on the rear surface side of the power source module40. A ventilation hole49corresponding to the position of the ventilation hole96of the partition plate95and the position of the fan43is formed in a part close to the rear surface (B) in the side surface facing the CTL module10of the power source module40. In the present embodiment, the shape of the ventilation hole49is a convex shape which covers the area from the front fan43to the intermediate area between these fans. The shape of the corresponding ventilation hole96of the partition plate95is the same as that of the ventilation hole49or a shape covering the same.

The fan unit42has a redundant configuration to cool the inside of the basic chassis100by the operation of a plurality of fans (air blowers)43. In the present embodiment, the fan unit42is similarly provided with two fans43each in the upper and lower areas corresponding to the upper and lower two CTL modules10, and further, it is provided with two (duplex) fans43aligned in a back-and-forth direction (in tandem). In this configuration, total of four fans43are provided in one power source module40. As the fan43, for example, a fan such as an axial-flow fan is used.

By a blade rotational motion by a DC power supply, each fan43takes air from an air-intake port facing the front surface (A) and exhausts the air from the exhaust port facing the rear surface (B). By the operation of the fan43, the cooling air which flows in from the rear surface side of the power source module40and is warmed through the power source unit41and the cooling air which is warmed through the CTL module10and flows into the vicinity of an air intake port through each ventilation hole (105,96, and49) are taken in from the air intake port, and then exhausted to the outside of the basic chassis100from the exhaust port in the back and the exhaust hole48of the power source module40.

In the fan unit42, since the duplex (plural) fans43are provided, even when one fan stops rotating, the cooling effect can be secured by the operation of the other fan. Further, even when the fan unit42in one of the left and right power source modules40stops rotating or even when the fan unit42is not installed in one of them, the cooling performance can be secured by the operation of the fan unit42in the other power source module40. In that case, the cooling air in the CTL module10flows into the fan unit42of the power source module40operating normally.

Next, for comparison purpose, a configuration (chassis, module and cooling structure) in the disk array system of the conventional technology (background technology) of the present embodiment will be briefly described below. In this conventional technology, in the basic chassis, modules such as the HDD group, the battery, and the like are installed in the front part, that is, on the front surface side from the backboard. Also, three types of modules such the CTL, power source, and fans and duplicated modules thereof, that is, a total of six modules are installed in the rear part, that is, on the rear surface side from the backboard. In the rear part, two CTL modules are adjacently disposed up and down in the upper area, and two power source modules are adjacently disposed side by side in the lower area. Two fan modules are disposed on both left and right sides of these modules. That is, in this configuration, power source module and fan module are separated. The HDD is, for example, a HDD of a fiber channel I/F. Further, in the expanded chassis, the modules of the HDD group are installed in the front part, that is, on the front surface side from the backboard. Two types of modules of the ENC and the power source and duplicated modules thereof, that is, a total of four modules are installed in the rear part, that is, on the rear surface side from the backboard. In the rear part, two ENC modules are adjacently disposed side by side in the upper area, and two power source modules are adjacently disposed side by side in the lower area.

<Design of Basic Chassis and Module>

The outline of the design for the basic structure of the basic chassis100and the layout of each module in the chassis in the present embodiment will be shown in the following (1) to (5). Basically, based on the mounting details of the modules, required specifications, and the like, the shape, size, layout, and the like of the module are designed, with taking into consideration the prevention of the interference between the connectors in the backboard20and the cooling structure in the chassis and the size reduction thereof (size standard and the like). With respect to the connector interference, the design is made so that the positions of the connectors to connect each module do not overlap one upon another and they are not located too close in the front and rear surfaces of the backboard20.

(1) The layout of the HDD modules30is determined. Since the specification basically requires the mounting of the SAS-HDD31, the position of the connector32on the side of the HDD31of the HDD module30and the position of the corresponding connector203on the side of the backboard20are determined. Specifically, the positions of the connectors (32and203) are located in the center zone of the backboard20as shown inFIG. 12andFIG. 13. Further, in the front part1, the battery module50and the like are disposed below the HDD module30, and the configuration of the front part1is thus roughly determined. Also when the SATA-HDD35is installed, because of the interposition of the path control board37, the chassis has approximately the same configuration as the case of SAS-HDD31in its entirety. By the change in the specification from the conventional configuration, the position of the connector32of the SAS-HDD31for the backboard20of the present configuration differs from the conventional position of the connector of the HDD of the fiber channel I/F for the backboard (moved from upper area to the center zone).

(2) The layout of the CTL module10is determined. The position of a connector111of the CTL module10and the position of the corresponding connector201on the backboard20are determined so as to prevent the connector interference in the backboard20, in particular, to prevent the overlap with the position of the connector32of the HDD module30of the item (1). Specifically, the positions of the connectors (111and201) are located at the positions near the upper and lower sides of the backboard20as shown inFIG. 12andFIG. 13. In the conventional configuration, the two power source modules are disposed below the two CTL modules (#1and #2), and the connector of one CTL module (#2) is disposed near the center of the backboard. In the present configuration, in the rear part2, the conventional two power source modules are moved to the left and right side areas (power source module40), and two CTL modules (10) only are adjacently disposed up and down in the area between the power source modules. By this means, the position of the connector of one (lower side) CTL module (#2) is moved further downward than the conventional position.

(3) The layout of the power source module40is determined. According to the item (2), though the power source modules40are disposed in the left and right side areas (B2) of the chassis, since the fan modules exist in these areas in the conventional configuration, the power source modules40are integrated with the fan modules. More specifically, this power source module40is a combination type containing the power source unit41and the fan unit42. Further, the positions of the connector45of the rear surface of the power source module40and the corresponding connector204on the backboard20are determined so as to prevent the connector interference. Specifically, the positions of the connectors (45and204) with a longitudinal rectangular shape are located near the left and right sides of the backboard20as shown inFIG. 12. The connectors of the power source module of the conventional configuration are disposed near the lower side of the backboard. In the present configuration, however, these connectors are unified with connectors of the left and right fan modules and are moved to the positions near the left and right sides of the backboard20. In this manner, the configuration of the rear part2is roughly determined.

(4) Next, the structure of the flow path (and the flow amount and the like) of the cooling air from the front surface (A) of the front part1to the rear surface (B) of the rear part2of the basic chassis100through the backboard20is considered and designed. The layout and size distribution of the module mounting area in the chassis, the layout of the partition plate and ventilation hole, the layout, area, and the like of the opening hole220of the backboard20are considered and designed. Further, the design of the flow path is considered so as to equalize the flow amount to each duplex component (CTL modules10and the like).

(5) Further, in particular, the details of the cooling structure of a combination of the CTL module10and the power source module40in the rear part2are determined. Specifically, the cooling air flow path is determined by the layout of the fan unit42, the ventilation hole96of the partition plate95, and no provision of the ventilation hole in the front surface (106) of the CTL module10. Further, as the cooling structure in the CTL module10, the position of the cooling object components (IC and the like) and the shape and position of the corresponding block150are devised.

InFIG. 10andFIG. 11, the basic cooling structure in the basic chassis100is as follows. By the operation of the fan43of the fan unit42, the outside air is taken in the front part1from the front surface (A), passes between the HDDs31and like as a cooling air, and then flows into the rear part2through the opening hole220of the backboard20. In the rear part2, the cooling air is divided and flows into the CTL module10and the power source module40, respectively. By the partition plate95between the power source module40and the CTL module10, the cooling air is separated and rectified. Further, by the partition plate between the two CTL modules10, the cooling air is separated into the upper and lower areas.

In the rear part2, the cooling air passes and cools each component in the CTL module10and the power source unit41in the power source module40, respectively. Such cooling air is drawn by the fans43in the power source module40and is exhausted outside from the exhaust hole48of the power source module40on the side of the rear surface (B). In the CTL module10, the cooling object components are efficiently cooled by the area114with the duct structure formed by the block150. From the inside of the CTL module10to the inside of the power source module40, the cooling air flows into the fan43through the ventilation hole96(and the corresponding ventilation holes105and49) and the like of the partition plate95. The position of the ventilation hole96in the partition plate95between the CTL module10and the power source module40is not in the entire surface of the partition plate95but at a part close to the fan unit42on the rear side of the chassis. By this means, the cooling air is rectified and the cooling efficiency can be enhanced. The front surface106of the CTL module10is closed.

The cooling air flow path in the configuration in the basic chassis100and the flow amount and flow distribution therein will be described with reference toFIG. 10andFIG. 11. InFIG. 10, the distribution of the flow amount in this plane, for example, is as follows. It is assumed that a flow amount10flows into the front part1(the HDD module30group) from the front surface (A). In the rear part2, the module layout, the area of the opening hole220and the like are designed so that the cooling air is equally distributed to the CTL module10and the power source module40. More specifically, when considering one area of the upper and lower sides in the chassis, a flow amount of 5 of the flow amount of 10 from the front part1flows into one CTL module10, and a remaining flow amount of 5 flows into the left and right power source modules40in total (individually flow amount of 2.5). In the CTL module10, a flow amount of 2.5 of the flow amount of 5 is separately supplied to each of the left and right power source modules40and drawn into the fan unit42(fans43). In the fan unit42of each of the left and right power source modules40, the flow amount of 2.5 from the power source unit41and the flow amount of 2.5 from the CTL module10are drawn, and a total of the flow amount of 5 is exhausted outside.

Further, the cooling air flown into one CTL module10of the rear part2from the opening hole220of the backboard20cools each component (shown by rectangle) such as an IC and a heat sink (112) formed thereon provided on a CTL substrate (120). The cooling air flows toward the rear surface (B), and after cooling each component, it passes through the ventilation holes96(and the corresponding ventilation holes105and49) of the left and right partition plates95and is drawn by the fans43in each power source module40from inside of the CTL module10.

Further, inFIG. 11, for example, the distribution of the flow amount in this plane is as follows. It is assumed that the flow amount of10flows into the front part1from the front surface (A). The module layout, the area of the opening hole220and the like are designed so that the flow amount is distributed at the rate of 8:2 in the HDD module30and the battery module50. In this design of the configuration, the HDD module30is more efficiently cooled than the battery module50. The flow amount is equally (5:5) distributed to the two (duplex) CTL modules10of the rear part2. From the HDD module30of the front part1, a flow amount of 5 of the flow amount of 8 flows into the upper CTL module10(CTL #1) and a remaining flow amount of 3 flows into the lower CTL module10(CTL #2). From the battery module50of the front part1, a flow amount of 2 flows into the lower CTL module10(CTL #2). The flow amount of 5 in each of the upper and lower CTL modules10is drawn by the fan unit42in the power source module40and is exhausted outside (broken line arrow mark).

Next, the cooling structure of the CTL module10will be described in detail with reference toFIG. 15toFIG. 18and the like.

FIG. 15shows a structure of the CTL module10in a disassembled state. After storing and connecting component parts such as a CTL substrate (control package)120, a host I/F unit103, and a block150serving as a filler in a main body101of the CTL module10, a top cover102serving as the upper surface is attached by screws and the like.

The CTL substrate120is attached to the bottom surface of the main body101. The main body101and the top cover102are mainly a package made from metal plate and they form the most part of the outer shape of the CTL module10. The areas for the ventilation holes105corresponding to the layout and shape of the ventilation holes96provided in the partition plate95at the boundary with the power source modules40are provided on both side surfaces of the main body101. In the present embodiment, the shape of the ventilation hole105is a horizontal rectangular by a plurality of slits. The front surface106(the rear surface (B) side of the basic chassis100) of the may body101has a notched area corresponding to the attachment of the host I/F unit103. The host I/F unit103includes a substrate, a front panel, terminals and others. The connector111and the like of the CTL substrate120are exposed on the rear surface side of the main body101.

Further, various terminals, display elements, and the like are mounted in a part of the area of the front surface106of the CTL module10, particularly in an area107near the center of the lower side thereof. In this area107, for example, a display LED, LAN terminal, backend system terminal, remote adaptor terminal, UPS terminal and the like are mounted.

Further, on the left and right sides of this area107, that is, at the bottom left and right corners of the front surface106, the operating levers104are provided. The operating lever104is, for example, a mechanism of fixing and releasing the CTL module10to and from the chassis by the operation of rotating a lever main body on a fixing axis (support point) at the corner of the CTL module10, that is, the operation of putting up and down the lever main body on the front surface106of the CTL module10. When fixing the module, the lever main body is put down so as to be in parallel with the front surface106. By this means, its one end (side surface side) is hooked on the structure (receiving portion) on the side of the partition plate95of the chassis, and the other side (inner side) is latched on the structure (receiving portion) on the side of the front surface106of the CTL module10.

The block150is, for example, a structure made of a foamed material. The block150having a layout and shape corresponding to the cooling objects (including the heat sink112) on the CTL substrate120is attached onto the lower surface (area114) of the top cover102. The block150forms a part of the cooling air flow path (in other words, the duct) in the CTL module10. Incidentally, in the heat sink112illustrated here, the details of fins and the like are omitted.

FIG. 16shows a component layout in the CTL substrate120, the main body101of its periphery, and the ventilation hole105. The CTL substrate120has a roughly flat-plate shape by a substrate113. A connector (BB connection connector)111for the connection to the backboard20is provided on one side of the CTL substrate120. On the substrate113of the CTL substrate120, for example, main parts such as ICs are installed in accordance with the layout as illustrated. These parts generate a relatively large amount of heat by the operation thereof and are the components in which particular consideration must be given to the cooling performance. These cooling objects include, for example, a CPU121, a SAS expander (EXP)122, a bridge123, a DCTL124, a SAS interface controller (SAS-CTL)125(consideration is given by including the heat sink112installed on the IC and the like). The CPU121corresponds to the CPU11. The bridge123corresponds to the bridge12. The DCTL124corresponds to the DCTL15. The EXP122and SAS-CTL125correspond to the SW18. In the present embodiment, in about half the area on the side close to the connector111of the substrate113, the block150is disposed in the area114above the cooling object components including the CPU121to DCTL124(including the heat sink).

Further, in the present embodiment, a temperature sensor115is provided in front of the CPU121on the side close to the connector111on the substrate113. Based on the temperature (temperature in the chassis) detected by the temperature sensor115, a fan control described later is performed. Also in the ENC module70, similarly to the CTL module10, the temperature sensor115is provided. In the CTL110and ENC170, the fan control is performed by the environment management unit (K)22.

The flow (arrow mark) of the cooling air to the cooling object components on the CTL substrate120will be described. That is, the cooling air which flows into the CTL module10first cools the periphery of the cooling object (#1)131including the CPU121and the EXP122provided in the vicinity of the connector111on the CTL substrate120. Subsequently, the cooling air flows toward the rear surface (B) and cools the periphery of the cooling object (#2)132including the bridge123and the DCTL124located at the latter stage of the cooling object131at the former stage. Then, the cooling air flows further backward and cools other components such as the SAS-CTL125near the rear surface (B). After each component in the CTL module10is cooled, since the front surface106of the CTL module10is closed, the cooling air passes through the ventilation hole105of the main body101of the rear part (close to the rear surface (B)) and is drawn into the power source module40from the CTL module10.

For the improvement in efficiency of ventilation/exhaust by the fan unit42, the exhaust hole and the like are not provided in the front surface106of the CTL module10(closed as the flow path). Accordingly, the air once exhausted outside from the fans43does not flow (circulate) into the CTL module10.

InFIG. 17, the structure of the block150is shown by a three-side view and an isometric view. The block150forms the cooling air flow path (duct structure) when disposed in the CTL module10. The block150has a shape based on a main body with a roughly rectangular section provided with concavity and convexity. In the block150, concavity and convexity are formed to the main body thereof so that a space for the flow path corresponding to the layout and shape of the cooling object components (131and132) is formed. Further, in the block150, the side of the main body thereof adjacent to the upper surface (top cover102) of the CTL module10serves as a space for the ventilation, and a hole (conduit in the block)151passing from that space to the cooling object component132in the CTL module10is formed. Because of the block150, the cooling air flow path (duct) can be configured to have a shape capable of efficiently cooling the cooling object components (131and132) and having rectifying effect.

FIG. 18schematically shows a cooling air flow path in the periphery of the block150in the CTL module10by a section in the direction of the side surface of the chassis. In the block150, slopes (inclination) by a trapezoid are formed in the portions corresponding to the side where the cooling air flows in and the side where the cooling air flow out. Because of the slopes, the flow of the cooling air is smoothed, and the cooling air can be efficiently applied to the cooling object component131. The slope is not limited to that having a flat surface, and the one having a curved surface is also available. The one air (intake air) taken in from the rear surface side of the CTL module10shown by a is guided by the slope of the block150and is applied to the cooling object component131(for example, EXP122) on the former stage, and the other air passes through the flow path by the hole151and the like of the block150and is directly applied to the cooling object component132(for example, DCTL124) on the latter stage. The cooling air which flows out from the slope on the rear side of the block150is supplied (exhausted) backward (front surface106side) in the CTL module10as shown by b and is drawn by the fan unit42of the power source module40.

Incidentally, the inflow of the cooling air into the inner space and the hole151of the block150is, for example, from the lower surface of the top cover102. Further, for example, the structure in which the air flows from a notched part formed in the slope of the block150into the inner space of the block150and then reaches the hole151is also possible. The block150can have any shape as long as the cooling air can be directly applied to the cooling object component132of the latter stage, and various types can be used.

Since the cooling air flowing into the CTL module10is immediately applied to the cooling object components (#1)131, for example, the EXP122and the CPU121close to the connector111side, the cooling performance of the components is relatively high. Meanwhile, since the air once warmed through the EXP122and the like is applied to the cooling object components (#2)132, for example, the bridge123, the DCTL124, and the like adjacent to the back thereof, the cooling performance is relatively deteriorated. To cope with the situation, in the present embodiment, by branching the cooling air flow path by means of the structure of the block150, the cooling air is directly applied also to the cooling object component132of the latter stage. In this manner, the cooling performance of the cooling object component can be enhanced.

Next, a fan control in the disk array system5will be described. The operation of the fan unit42in the power source module40is controlled (fan control) mainly by the environment management unit (K)22, for example, the CTL110and the ENC170, thereby adequately controlling the temperature state of the system. The processing for the fan control is realized by a program processing by a processor corresponding to the environment management unit (K)22or a hardware logical circuit. In the fan control, the environment management unit (K)22detects the temperature (temperature in chassis) by the temperature sensor115and performs a control (temperature control) to automatically switch the operation mode of the fan unit42(fans43) based on the detected temperature. As the operation mode, various types of modes different in rotation speed such as the fastest mode (abnormal time and the like), the high speed mode (intensive cooling time), the intermediate speed mode (normal time), and the low speed mode (waiting time) are provided.

In this temperature control, for example, when the sensor detection temperature is within the normal range, the control is set to the intermediate speed mode, and when it reaches the predetermined temperature or more, the mode is switched to the high speed mode. By setting the high driving voltage, the number of rotations (rotation speed) of the fan is increased, and the flow amount of the cooling air is increased. In this manner, regardless of the presence of failures, the cooling performance can be secured. Incidentally, the cooling performance is converted as [sensor detection temperature (temperature in chassis)]=[outside temperature (environmental temperature)]+[0 to 7° C.]. For details, the change in the number of fan rotations by the driving voltage is made by the switchover of a duty ratio of the input pulse to the fan43(pulse frequency to the fan specification).

Further, as the conventional technology, the control in which the fan rotation speed is switched when the troubles and connections of the CTL, power sources (PS), fans and the like are detected in association with the maintenance and replacement services has been known (trouble detection control and abnormal time control). In the disk array system5, the trouble detection control and the temperature control described above are combined together when performing the fan control.

In the trouble detection control, when the trouble of a part of the fan unit42or the fan43, that is, a trouble, an operation stop, a disconnected state, and the like are monitored and detected, by the adjustment of the driving voltage for the fan unit42, the operation of the fan unit42(fans43) normally connected at that time is switched to the operation mode so as to increase the rotation speed. For example, the operation mode is switched from the intermediate speed mode to the high speed mode. By this means, the flow amount of the cooling air is increased, thereby compensating for the decrease of the cooling performance due to the trouble. Even when one of the left and right fan units42(a part of the fan43) are out of service, the cooling performance of the CTL110and the like can be secured. When restored to the normal state, the operation mode is returned to the intermediate speed mode or others.

The control conditions of this fan control are as follows. That is, the intermediate speed mode (or the low speed mode) is used when the temperature in chassis is less than 39° C., and when it is 39 to 47° C., the high speed mode is used, and when it is 47° C. or more, the fastest mode is used. Further, at the time of the system abnormal state, the operation mode is set to the fastest speed mode. The number of rotations of the fan at each operation mode is, for example, 3240 to 4112 rpm for the low speed mode, 5400 to 6890 rpm for the intermediate speed mode, 8100 to 10300 rpm for the high speed mode, and 10800 rpm or more for the fastest speed mode. Further, the system abnormal state includes, for example, a state where one CTL is removed (disconnected state of the one CTL module10), a state where one PS is removed (disconnected state of the one power source module40), a state where one PS is in an abnormal state (abnormal state of the one power source module40), a state where the number of fan rotations is insufficient (abnormal state of the fan43), and the like. Also, in the system abnormal state, an alarm (warning) is outputted together with the fan control. For example, when the state where the number of fan rotations is sufficient is detected successively a predetermined number of times (more than the predetermined period), an alarm by means of an LED lighting, a message, and sound is outputted. Incidentally, even when the system is in an abnormal state, when one of the duplex modules normally operates, it functions as the disk array system.

InFIG. 19, the processing flow of the fan control in the basic chassis100and the CTL110is as follows (S denotes the processing step). At S1, when the CTL110is turned on (S1-Y), the temperature detected by the temperature sensor115(temperature in chassis and the CTL intake air temperature) is checked at S2. When the temperature is less than the predetermined value, that is, when the temperature in chassis is less than 39° C. in the present embodiment (environment temperature is 32° C.) (S2-Y), in other words, when the environment temperature is in the normal range, a fan connection state to the chassis is determined at S3. More specifically, it is determined whether the left and right two fan units42(each four fans43for the left and right sides) of the chassis are normally connected to the CTL110. Preferably, the state of a plurality of fans43is determined individually. When the left and right two fan units42are both connected, that is, when all the fans43are in a normal connected state (S3-Y), unless the system is in a waiting state (no data input/output state) (S4-N), each fan unit42(each fan43) is driven in the intermediate speed mode by the predetermined driving voltage at S7. Further, when the system is in a waiting state (S4-Y), the fan unit42(each fan43) is driven in the low speed mode at S6. When the power of the CTL110is turned off (S10-Y), the operation of each fan unit42is stopped, and when it is not turned off (S10-N), the processing returns to S2.

Further, when the left and right fan units42are in a state of being not normally connected (S3-N) at S3, that is, when only one fan unit42(or apart of the fans43) is operating, the connected fan unit42(or the fans43) is driven in the high speed mode at S8.

Further, when the temperature (temperature in chassis) detected by the temperature sensor115is the predetermined value (39° C.) or more at S2(S2-N), the mode is changed to the high speed mode or the like. In this case, since the environment temperature is higher than the normal range, this is considered as a highly heated state due to a high load of the CTL110, a troubled state or a system abnormal state due to some causes. As for the troubled state, the failure of one fan unit42(or a part of the fans43) and the disconnected state and the like are considered. At this time, the temperature state and the state of the fan unit42(fans43) and the like are determined at S5. More specifically, it is determined whether the temperature in chassis is equal to or higher than the predetermined value, in this embodiment, it is 47° C. or higher or whether the system is in an abnormal state. When the temperature is less than the predetermined value (47° C.) or when the system is not in the abnormal state (S5-N), the fan unit42(fans43) is driven in the high speed mode at S8, and when the temperature is equal to or more than the predetermined value (47° C.) or when the system is in an abnormal state (S5-Y), the fan unit42(fans43) normally connected is driven in the fastest speed mode at S9.

FIG. 20shows the flow of the cooling air at the time when only one of the left and right power source modules40(fan unit42) of the basic chassis100is operated. For example, it corresponds to the state where one PS is in an abnormal state or the state where one PC is removed, and the state where the right power supply module (#2) relative to the rear surface (B) is not connected or troubled is shown here. By the fan control described above, the operation of the fan unit42of the left power source module40(#1) normally connected and operated is switched to the high speed mode or the fastest speed mode. By this means, the cooling air (each cooling air of the CTL modules (#1and #2)10and each cooling air of the power source units (#1and #2)41) in the rear part2are all drawn and exhausted by the fan unit42of the normal one (#1). Accordingly, the cooling performance particularly in the CTL module10is also secured.

In the fan unit42, when one of the fans43aligned in a back-and-forth direction is in trouble, the cooling performance is secured by the operation of the other fan. Further, when one of the upper and lower fans43is out of order, the cooling performance is secured by the operation of the other fan.

<Effect of the Embodiment>

As described above, according to the present embodiment, the following effect can be obtained. In the present embodiment, the new structures for the chassis and modules as well as the cooling structure are realized in consideration of the high density mounting and the cooling performance. Particularly, in the basic chassis100, the size reduction is realized by the reduction of the number of modules (CTL modules10installed up and down and the power source modules40disposed left and right). Further, with respect to the cooling performance, because of the exhaust in the left and right power source modules40(fan unit42), the structure of the backboard20(connector position and opening hole220), the ventilation hole96of the partition plate95, the duct structure by means of the block150in the CTL module10, and the fan control using the temperature sensor115, the efficient cooling of each unit of the CTL board120can be realized in both the normal state and the abnormal state. Since the cooling performance can be secured, the improvement of the processing performance and the reliability of the disk array system can be achieved.

Incidentally, although the structure of the basic chassis having the HDD31has been described inFIG. 4toFIG. 20, the present invention is not limited to this. For example, it can be applied to the basic chassis having no HDD31. Further, although the structure of the basic chassis100has been described inFIG. 4toFIG. 20, the present invention can be applied not only to the basic chassis100but also to the expanded chassis200. In this case, inFIG. 4toFIG. 20, the enclosure (ENC) is mounted in the position where the controller (CTL) is installed.

The present invention can be used for equipment such as the disk array system.