COMPUTER SYSTEM WITH DUMMY DRIVE FOR OPTIMAL COOLING EFFICIENCY

Abstract: A data processing system or data storage system to be connected to a processor require cooling of electronic components. Systems with unused disk drive slots are mounted with dummy disks to provide an air flow resistance effective to substantially duplicate the air flow of a functional disk drive located in a disk drive bay. Cooling air flow is directed to functional components for maximal cooling efficiency.

Description: TITLE: COMPUTER SYSTEM WITH DUMMY DRIVE FOR OPTIMAL COOLING EFFICIENCY BACKGROUND OF THE INVENTION 1. Field of the Invention The invention is related to the field of computer systems, and more particularly to air flow cooling of computer systems configured to contain at least one disk drive. The invention is also related to computer subsystem configurations, and the maintenance of optimal air flow and cooling of functional components in a computer system that contains unused disk drive slots. 2. Description of the Relevant Art A typical computer system includes multiple electronic components, including a central processing unit or "processor", positioned within an enclosure and data storage components such as disk drives. Certain systems include external or internal data storage subsystems that are variously configured. Such subsystems may include a RAH) (redundant array of inexpensive disks) or a JBOD (just a box of disks) configuration, and may include multiple electronic components including disk drive subassemblies. During operation, such electronic components dissipate electrical power (i.e., transform electrical energy into heat energy). At the same time, several key operating parameters of semiconductor electronic devices typically vary with temperature, and reliable device operation within specifications occurs only within a defined operating temperature range. For example, specified performance of a processor is typically achieved only when the temperature of the processor is maintained below a specified maximum operating temperature. Operation of the processor at a temperature above the maximum operating temperature may result in irreversible damage to the processor. In addition, it has been established that the reliabilities of semiconductor electronic devices decrease with increasing operating temperature. The heat energy produced by electronic components during operation must thus be removed to a surrounding ambient at a rate that ensures operational and reliability requirements are met. As component speeds and capabilities increase, so does the amount of electrical power dissipated by the components during operation. Cooling mechanisms employed by computer systems must thus transfer more heat energy from the computer system enclosure to the surrounding ambient. A hard disk drive enclosure is often an external cabinet that contains multiple hard drives for data storage and is connected to a computer system. Such a cabinet may contain many disk drive slots, each configured to receive a disk drive. Often a system is sold with less than the full capacity of disk drives, thus leaving some of the slots unoccupied and available for future increased data storage capacity. The cooling system in a hard disk drive enclosure is critical and must be designed to handle the maximum heat load, e.g. when all the disk drive slots contain functional disk drives. When an enclosure is sold as an entry level system with a minimum number of drives installed, the unoccupied areas of the cabinet may cause an imbalance in the air flow. In a system with less than the full capacity of drives installed, the majority of the cooling air flows through the large gaps within the system reserved for future disk drive installation, rather than flowing across the installed, functional disk drives where the cooling is needed. SUMMARY OF THE INVENTION The problems outlined above are in large part solved by a computer or data storage system that includes one or more dummy drives for installation in any vacant disk drive slots or positions. A dummy drive, as disclosed herein, may have a shape that substantially duplicates the three-dimensional shape of a disk drive, particularly a hard disk drive, including the hard drive assembly (HDA) and any brackets, carriers, or latching mechanisms that may be attached to a hard drive assembly. A dummy drive may be mounted or placed in an unoccupied disk drive slot in a system, and would then substantially duplicate the air flow resistance of a functional disk drive that may or may not be mounted in that slot at some future time. When all unused disk drive slots have a dummy drive installed, the interior of the system has substantially the air flow characteristics of a system with a full capacity of functional disk drives. This arrangement allows the cooling system air to cool the functional disk drives at maximal efficiency. As new functional disk drives are added to the system, a dummy drive in the selected slot may be removed and replaced with the functional disk drive. It is also understood that it is not required that all available disk drive slots have a functional disk drive or a dummy disk in order to improve the air flow and cooling efficiency of the system. Any use of one or more dummy drives as disclosed herein would fall within the spirit and scope of the present disclosure. In certain embodiments a dummy drive as disclosed herein may be a non-functional hard drive assembly with the connectors disabled or removed. For example, such a hard drive assembly may have the connector removed, or it not include a hard disk, or it may not include any functional electronic components. The hard drive assembly would thus have the outer shape of a disk drive and would be effective in the practice of the present invention. Dummy disks may also be molded from an inexpensive material, such as a plastic, a polymer, a polyfoam plastic, a polystyrene or even expanded polystyrene material. The material may preferably be flame retardant so as to pass appropriate safety agency requirements for components inside a computer system. The dummy drives may be designed to mimic the appearance of functional drives including any bracket, carrier, latch or other attachments to the hard drive assembly. For example, a bracket or carrier may be attached to a hard drive assembly in order to configure that assembly for mounting in a particular system. A geometry substantially duplicating the shape of any of such hardware or attachments may also be incorporated into a dummy drive. A dummy drive may also include instructions molded into or attached to each dummy drive for installation, removal and/or replacement of the dummy drives as necessary. It is contemplated that the dummy drives may be discarded when they are replaced in the system with functional drives. Dummy drives as disclosed herein may be used in any type of device or cabinet that has the capacity to contain disk drives, particularly those that contain multiple hard disk drives. Such devices would include, but are not limited to personal computers, any computer system with an electro-mechanical mass storage device or with connection to such a device, and external mass storage devices. Some such devices contain arrays of hard disk drives connected in a manner known in the field as RAID (redundant array of inexpensive disks), JBOD (just a box of disks) or by other acronyms or names that indicate a number of disks connected to a processor for mass data storage. External data storage devices or cabinets that are known in the art include deskside towers or rack mounted cabinets that are configured to contain a number of disk drives. A "hard disk," as used herein, indicates a disk in which the storage media is not routinely removable separately from the drive, as is the case with a floppy disk or a CD-ROM. The definition of a hard drive does include a "hot swap" or "hot swappable" drive m which the entire hard drive is removable by the operator for secure overnight storage, for example. As used herein a disk drive "slot" is meant to indicate a space provided for installation of a disk drive, including any rails, channels, or other configuration incorporated into a cabmet or system to accommodate a disk dπve. BRIEF DESCRIPTION OF THE DRAWINGS The following drawings form part of the present specification and are mcluded to further demonstrate certain aspects of the present invention The invention may be better understood by reference to one or more of these drawings m combination with the detailed description of specific embodiments presented herein. FIG. 1 is a perspective view of an exploded external data storage system configured to contain 8 disk drives. FIG. 2 is a perspective view of a data storage system with several empty hard drive slots FIG. 3 is a perspective view of a data storage system with one empty hard dπve slot. FIG 4 is a perspective view of a data storage system with 8 hard dπves installed and 4 dummy drives installed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Figure 1 is an exploded view of an embodiment of an external data storage cabmet 10 that is configured to connect to a processing unit. The device mcludes side skins 40, a bottom 42, a top 44, and feet 46. The rear panel is not shown. The cooling system for this cabmet compπses two fan trays 12 that are disposed along the sides of the rear portion of the cabmet when assembled. The fans m this embodiment are centrifugal fans, configured such that the intakes 14 face a chamber 22 that contains two power supplies 16 (only one is shown m the drawing) and a controller board (not shown) that provides connection from the disk dπves to a processmg unit. The fan exhaust openings are to the rear 18 of the fan trays. A connector board 20 separates the chamber 22 from the disk dπve bays 24. The cabmet 10 shown m Figure 1 is designed to hold eight 1.6" disk dπves as can be seen by the eight connectors 26 on the connector board 20. Other embodiments of a data storage cabmet may provide slots and connectors for twelve 1 " disk dπves Of course, the number and sizes of the dπves is dependent on the size and design of the cabmet, and any cabmet or device configured with connections for a hard disk dnve could embody the present invention if dummy dnves are used. It is also understood that any size or shape of disk dπve can be duplicated m light of the present disclosure in order to replace any embodiment of a functional disk dπve. All such uses are mcluded m the scope of the present disclosure. Although the drawings attached hereto are directed to a stand alone cabmet, dummy dπves as disclosed herem may be used m any type of device or cabmet that has the capacity to contain disk dnves, particularly those that contain multiple hard disk dπves. Such devices would include, but are not limited to personal computers, any computer system with an electro-mechamcal mass storage device or with connection to such a device, and external mass storage devices as shown herem. Some such devices contain arrays of hard disk dπves connected m a manner known in the field as RAID (redundant array of inexpensive disks), JBOD (just a box of disks) or by other acronyms or names that indicate a number of disks connected to a processor for mass data storage. A RAID system mcludes mirrored data on more than one disk to provide backup m the event that a disk becomes inoperable or otherwise unreadable. A JBOD configuration includes multiple disks connected to a processor, but each individual disk may be independently connected, and the disks are not necessarily redundant. External data storage devices or cabinets that are known in the art include deskside towers or rack mounted cabinets that are configured to contain a number of disk drives. In the cabinet shown in Figure 1 , the disk drives stand in the bays 24 in vertical orientation and connect to the connectors 26 on the connector board 20 at the rear of the disk drive bays 24. The front of the cabinet 10 includes a bezel 28 and a door 30. Attached to the front of the door 30 is a grill 32 which serves as the intake for the air cooling system. In the pictured embodiment, the cooling air flow is drawn in through the grill 32, passes over and around the disk drives in the disk drive bays 24, passes through openings in the connector board 20 and into the chamber 22. In the chamber, the air is drawn across the controller board and the power supplies 16, into the fan tray intake openings 14, and is exhausted out to ambient through the rear of the fan trays 18. An embodiment of a cabinet 100 with 12 hard drive slots is shown in Figures 2-4. Hard disk drives 102 are installed in 8 of the slots. One hard disk drive 104 is partially removed for purposes of illustrating the invention. One dummy drive 106 is installed in the device, and a second dummy drive 108 is removed. A latching mechanism 120 is shown attached to the top of hard drive 104. Dummy drive 108 is molded with a projection 122 along the top to duplicate the shape of the latch device 120. As can be seen from Figure 2, the hard drive bay 24 on the right with 3 open hard drive slots is largely empty when compared with the bay on the left, in which all the slots are filled. Air being pulled through the grill 32 in the door 30 by the fan driven cooling system will naturally follow the path of least resistance, and would therefore flow through the large opening where no hard drives or dummy drives are installed, rather than across the functional hard drives where the cooling is needed. Figure 3 is a drawing of cabinet 100 in which 3 dummy drives are installed and 1 slot is empty. The cooling of this system would be more efficient than the configuration shown in Figure 2, but would not be optimal. Figure 4 illustrates the same cabinet 100 with all slots occupied by either a functional hard drive 102 or a dummy drive 106. In certain embodiments a dummy drive 106 as disclosed herein may be a non-functional hard drive assembly with the connectors disabled or removed. For example, such a hard drive assembly may have the connector removed, or it not include a hard disk, or it may not include any functional electronic components. The hard drive assembly would thus have the outer shape of a disk drive and would be effective in the practice of the present invention. Dummy drives 106 may also be molded from an inexpensive material, such as a plastic, a metal, a polymer, a polyfoam plastic, a polystyrene or even expanded polystyrene material. The material may preferably be flame retardant so as to pass appropriate safety agency requirements for components inside a computer system. It is an object of the present disclosure to provide an inexpensive, throw away device that is easily replaced as hard drives are acquired. Therefore, any inexpensive material can be used to make the dummy drives disclosed herein. The dummy drives may be designed to mimic the appearance of functional drives including any bracket, carrier, latch or other attachments to the hard drive assembly. As shown in Figure 2, a projection 122 that substantially duplicates a latching mechanism may be molded onto the dummy drive. Any other attachments normally used for hard drive installations, including a brackets or carriers may also be molded into the dummy dπve A dummy dπve may also mclude wπtten instructions molded mto or attached to each dummy dπve that explam installation, removal and/or replacement of the dummy dπves as necessary While the devices of this mvention have been descπbed m terms of prefeπed embodiments, it will be apparent to those of skill in the art that vaπations may be applied to the descnbed embodiments descπbed herem without departmg from the concept, spmt and scope of the mvention More specifically, it will be apparent that certain equivalent structures and methods may be substituted for those descπbed herem while the same or similar results would be achieved All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spiπt, scope and concept of the mvention as defined by the appended claims

Claims: WHAT IS CLAIMED IS: I . A data processmg system compnsing: a disk dπve slot, configured to contain a disk dπve; an air flow coolmg system configured to provide coolmg to a disk dπve contamed m said disk dπve slot; a dummy dπve mounted within said disk dπve slot and configured to substantially duplicate the air flow resistance of a functional disk dπve mounted within said disk dπve slot. 2. The data processmg system of claim 1 , wherem said system compπses a plurality of disk dπve slots. 3. The data processmg system of claim 1, wherem said disk dπve slot is contamed m a computer. 4. The data processmg system of claim 1 wherem said disk dπve slot is contamed m a data storage device configured to connect to a computer. 5. The data processmg system of claim 4, wherem said data storage device compπses a deskside tower cabmet. 6. The data processmg system of claim 1 , wherem said system compπses a plurality of disk dπve connectors configured m a "redundant array of inexpensive disks" (RAID) disk aπay. 7. The data processmg system of claim 1 , wherem said system compnses a plurality of disk dπve connectors configured m a "just a box of disks" (JBOD) array. 8. The data processmg system of claim 1, wherem said dummy disk compπses a fire resistant matenal. 9. The data processmg system of claim 1, wherem said dummy disk is disposable after use. 10 The data processmg system of claim 2, wherem each of said plurality of disk dπve slots contains a functional hard dnve or a dummy disk. I I . The data processmg system of claim 1 , wherem said dummy disk compπses a plastic or a polymer. 12. The data processmg system of claim 1 , wherem said dummy disk compπses polystyrene. 13. The data processmg system of claim 1 , wherem said dummy disk dπve is configured to substantially duplicate the three dimensional geometry of a functional disk dπve and mounting hardware. 14. A computer system comprising : an external data storage cabinet configured to contain a plurality of disk drives; an air flow cooling system configured to cool said disk drives; and one or more dummy disks configured to be mounted within said cabinet; wherein each of said one or more dummy disks, when mounted in said cabinet, substantially duplicates the air flow resistance of a functional disk drive configured to be mounted in said cabinet. 15. The computer system of claim 14, wherein said external data storage cabinet comprises a "redundant anay of inexpensive disks" (RAID) configuration. 16. The computer system of claim 14, wherein said external data storage cabinet comprises a plurality of disk drive connectors comprise a "just a box of disks" (JBOD) configuration. 17. The computer system of claim 14, wherein said one or more dummy disks comprise a molded polymer. 18. The computer system of claim 14, wherein said one or more dummy disks are configured to substantially duplicate the three dimensional geometry of a functional disk drive configured to be mounted in said cabinet. 19. A data storage cabinet configured to be connected to a data processing system, said cabinet configured to contain a plurality of disk drives and said cabinet comprising; an air flow cooling system configured to cool said disk drives; and one or more dummy disks configured to be mounted within said cabinet; wherein each of said one or more dummy disks, when mounted in said cabinet, substantially duplicates the air flow resistance of a functional disk drive mounted in said cabinet. 20. The data storage cabinet of claim 19, wherein said cabinet comprises a "redundant array of inexpensive disks" (RAID) configuration. 21. The data storage cabinet of claim 19, wherein said external data storage cabinet comprises a plurality of disk drive connectors comprise a "just a box of disks" (JBOD) configuration. 22. The data storage cabinet of claim 19, wherein said one or more dummy disks comprise a molded polymer. 23. The data storage cabinet of claim 19, wherein said one or more dummy disks are configured to substantially duplicate the three dimensional geometry of a functional disk drive configured to be mounted in said cabinet.

Inventors: GROUELL WILLIAM L, GROUELL, WILLIAM, L.
Applicants: SUN MICROSYSTEMS INC, SUN MICROSYSTEMS, INC.
Application year: 2000
Main classification: G11B33
IPC codes: G06F1, G11B33