Abstract:
A server system includes a cartridge cage including a power supply. The server system includes a plurality of server cartridges. Each server cartridge is configured to be inserted into the cartridge cage and be powered by the cartridge cage power supply. Each server cartridge includes a processor, memory, and a non-volatile storage device. Each server cartridge includes a case substantially surrounding the processor, the memory, and the non-volatile storage device. The server system includes a cooling subsystem positioned between the power supply and the plurality of server cartridges.

Description:
THE FIELD OF THE INVENTION 
     The present invention relates to server systems. More particularly, the invention relates to a server system with removable server cartridges. 
     BACKGROUND OF THE INVENTION 
     Server rack space and building floor space are at a cost premium, so it is desirable to obtain a high server density, especially in installations with hundreds or thousands of servers at one site, while also minimizing system cost. It is desirable in a rack-mounted server farm of “front end” servers, such as those commonly used for Internet web sites, to fit as many servers per “U” (i.e., per 1.75 inches of vertical rack space) as possible. 
     Existing server solutions include low profile servers of 1U size, and low profile board-based servers having multiple cards that plug into a card cage. However, increasing CPU and disk drive power requirements make these two low profile approaches problematic. The increasing power trend requires the use of larger heat sinks and more efficient cooling schemes that are incompatible with the two low profile prior art approaches. A less than optimum cooling scheme can result in lower reliability. 
     With the two low profile server solutions discussed above, the installation or removal of individual servers is problematic. With the board-based servers, exposed printed circuit assemblies (PCAs) are handled, which could cause electrostatic discharge (ESD) failures. With the low profile servers of 1U size, it is time consuming to slide out one server, and install a second server. 
     It would be desirable to provide a server system with “hot swappable” server cartridges that may be added and removed from a server system on-line. Hot swappable cartridges have been used before in mass storage systems. For example, a “Starfish” system is a mass storage system that uses plug-in disk drive cartridges. However, hot swappable server cartridges for a server system have not been used. It would be desirable to provide a server system with hot swappable server cartridges, with a higher server density and reliability than current server systems, and without the disadvantages found in many current server systems. 
     SUMMARY OF THE INVENTION 
     One form of the present invention provides a server system including a cartridge cage having a power supply. The server system includes a plurality of server cartridges. Each server cartridge is configured to be inserted into the cartridge cage and be powered by the cartridge cage power supply. Each server cartridge includes a processor, memory, and a non-volatile storage device. Each server cartridge includes a case substantially surrounding the processor, the memory, and the non-volatile storage device. The server system includes a cooling subsystem positioned between the power supply and the plurality of server cartridges. 
     Another form of the present invention provides a server cartridge including a processor, memory coupled to the processor, and a non-volatile storage device coupled to the processor. A server case substantially encompasses the processor, memory, and non-volatile storage device. The cartridge includes an electrical connector for connecting the server cartridge to a backplane of a cartridge cage. The electrical connector is positioned near a back end of the server cartridge. The server cartridge further includes at least one local area network connector positioned near a front end of the server cartridge. 
     Another form of the present invention provides a server system including a cartridge cage. A plurality of removable power supply modules are configured to be positioned within the cartridge cage near a first end of the cartridge cage. A plurality of removable server cartridges are configured to be positioned within the cartridge cage near a second end of the cartridge cage. Each server cartridge is configured to be powered by one of the power supply modules. Each server cartridge includes a processor, memory, and a non-volatile storage device. A plurality of removable fan modules are configured to be positioned within the cartridge cage between the plurality of power supply modules and the plurality of server cartridges. The cartridge cage includes a backplane positioned substantially near a center of the cage for electrically interconnecting the power supply modules, the server cartridges, and the fan modules. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a server system according to one embodiment of the present invention. 
     FIG. 2 is a back view of the server system shown in FIG.  1 . 
     FIG. 3 is a cross-sectional view of the server system shown in FIG. 1 taken along section lines  3 — 3 . 
     FIG. 4 is a side view illustrating a simplified representation of major internal components of a server cartridge according to one embodiment of the present invention. 
     FIG. 5 is a front view illustrating a simplified representation of major internal components of a server cartridge according to one embodiment of the present invention. 
     FIG. 6 is an electrical block diagram illustrating major components of a server cartridge according to one embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. 
     FIG. 1 is a perspective view of a server system  100  according to one embodiment of the present invention. In one form of the invention, server system  100  is a front-end server system configured as a redundant array of inexpensive servers in network (RAISIN) system. Although only a single server system  100  is shown in FIG. 1, multiple server systems  100  may be positioned together in a rack. 
     Server system  100  includes six fan modules  102 , door  104 , cartridge cage  106 , nine server cartridges  108 , and nine latches  116 . Fan modules  102  are positioned near the center of cartridge cage  106 , and are removable from cartridge cage  106 . In one embodiment, fan modules  102  are hot swappable. Because fan modules  102  are separated from and not contained within server cartridges  108 , larger, high efficiency fans can be used. In one embodiment, each fan module  102  includes a 120 mm fan. Door  104  is hinged to cartridge cage  106  and closes to cover fan modules  102 . Each fan module  102  includes two light emitting diodes (LFDs)  115 . In one embodiment, the left LED  115  on each fan module  102  emits green light when the module  102  is plugged-in and powered on, and emits short bursts or flashes of green light when the fan module  102  receives a server ID command. A server ID command is typically used for servicing of server system  100 . In one embodiment, the right LED  115  on each fan module  102  emits green light when the module  102  is operating normally, emits yellow light when the fan module  102  experiences a functional problem (e.g., the fan stalls), and emits red light to indicate a safety issue (e.g., overheating). In one form of the invention, fan modules  102  are configured as an N+1 redundant cooling system for each group of 3 server cartridges  108 , where N represents the number of fan modules  102  needed for normal operation for each group of 3 server cartridges, and “1” represents the number of redundant fan modules  102  for each group of 3 server cartridges. In one embodiment, N=1, so there is one fan module  102  for normal operation and one redundant fan module  102  for each group of 3 server cartridges  108 . 
     Server cartridges  108  are positioned near a front portion of cartridge cage  106  and are removable from cartridge cage  106 . In one form of the invention, each server cartridge  108  is “hot-swappable” and may be inserted and removed on-line without turning off the power. In one embodiment, each server cartridge  108  is configured as a server appliance, and is not a general purpose server. In one embodiment, each server cartridge  108  is encased in a metal box, with a front end and back end of the metal box substantially covered with vent holes  110 . Each server cartridge  108  includes a handle  120  to facilitate insertion and removal of the server cartridge  108  from cartridge cage  106 . In FIG. 1, the server cartridge  108  positioned farthest to the right in cartridge cage  106  is shown partially removed. Latches  116  are hinged to cartridge cage  106  and may be pushed down over handles  120  to hold server cartridges  108  in place after insertion into cartridge cage  106 . In one form of the invention, latches  116  are positioned horizontally, rather than vertically, so multiple server systems  100  may be stacked on top of each other without interfering with the operation of latches  116 . In one embodiment, fan modules  102  and power supply modules  200  (shown in FIG. 2) also include handles  120  like those shown for server cartridges  108  to facilitate insertion and removal of the fan modules  102  and power supply modules  200 . And cartridge cage  106  includes additional latches  116  to hold fan modules  102  and power supply modules  200  in place after insertion into cartridge cage  106 . 
     Each server cartridge  108  includes two local area network (LAN) ports  112  and  114 , and two LEDs  118 . In one embodiment, LAN port  112  is configured for a 1000 Base T LAN, and LAN port  114  is configured for a 100 Base T LAN. In alternative embodiments, LAN ports  112  and  114  may be configured for 10/100/1000 Base T, Infiniband, or other type of network currently existing, or to be developed. In one form of the invention, LAN ports  112  are redundant. In one embodiment, the left LED  118  on each server cartridge  108  emits green light when the cartridge  108  is plugged-in and powered on, and emits short bursts or flashes of green light when the cartridge  108  receives a server ID command. A server ID command is typically used for servicing of server system  100 . In one embodiment, the right LED  118  on each server cartridge  108  emits green light when the cartridge  108  is operating normally, emits yellow light when the cartridge  108  experiences a functional problem, and emits red light to indicate a safety issue (e.g., overheating). 
     In one form of the invention, server cartridges  108  are configured as an N+M redundant server system, where N represents the number of server cartridges  108  needed for normal operation, and M represents the number of redundant server cartridges  108 . In one embodiment, N=8 for a single cartridge cage  106 , N=143 for a rack, and M=1 for a single cartridge cage  106 , although alternative embodiments use more than one spare server cartridge  108  per cage  106 . 
     In one embodiment, cartridge cage  106  is about 24 inches long, 18.25 inches wide, and 5.25 inches high (i.e., 3U), and each server cartridge  108  is about 13.5 inches long, 2 inches wide, and 5 inches high. In alternative embodiments, cartridge cage  106  is between about 22-26 inches long, 16-20 inches wide, and 4-6 inches high, and each server cartridge  108  is between about 12-15 inches long, 1.75-3.5 inches wide, and 4-6 inches high. In alternative embodiments, other dimensions and configurations are used, including a cartridge cage  106  configured to hold more or less than 9 server cartridges  108 . With 6 to 12 server cartridges  108  per 3U, the effective server U ranges between 0.25U and 0.5U. 
     FIG. 2 is a back view of the server system  100  shown in FIG.  1 . As shown in FIG. 2, three hot swappable power supply modules  200  are positioned near a back portion of cartridge cage  106 . In one embodiment, each power supply module  200  is encased in a metal box, with the ends of the metal box substantially covered with vent holes  208 . Each power supply module  200  includes a pair of LEDs  202 , and a power connector  204 . Power cables  206  are plugged into power connectors  204 . In one embodiment, power supply modules  200  are configured as an N+1 redundant power system, where N represents the number of power supply modules  200  needed for normal operation, and “1” represents the number of redundant power supply modules  200 . In one form of the invention, N=2, so there are two power supply modules  200  for normal operation, and one redundant power supply module  200 , to supply power to server cartridges  108  in cartridge cage  106 . In one embodiment, the power supply per 6-9 server cartridges  108  uses only 2-3 power cords, rather than one power cord for each server cartridge  108 . By powering multiple server cartridges  108  with a single power supply module  200 , larger, less expensive, and lower power density supply modules may be used. 
     In one embodiment, the left LED  202  on each supply module  200  emits green light when the module  200  is plugged-in and powered on, and emits short bursts or flashes of green light when the supply module  200  receives a server ID command. A server ID command is typically used for servicing of server system  100 . In one embodiment, the right LED  202  on each supply module  200  emits green light when the module  200  is operating normally, emits yellow light when the module  200  experiences a functional problem, and emits red light to indicate a safety issue (e.g., overheating). 
     FIG. 3 is a cross-sectional view of the server system  100  shown in FIG. 1 taken along section lines  3 — 3 . Back plane  302  is attached to cartridge cage  106 . Each power supply module  200  is connected to back plane  302  via a connector  300 . Fan modules  102  are connected to back plane  302  via connectors  304 . Each server cartridge  108  is connected to back plane  302  via a connector  306 . In one embodiment, each connector  300 ,  304 , and  306  is a low insertion force connector with a low accuracy requirement. In one form of the invention, server system  100  is reversible, so that server cartridges  108  are positioned at the back of server system  100 , and power supply modules  200  are positioned at the front of server system  100 . In one embodiment, air flows through server system  100  from front to back (i.e., from right to left in FIG.  3 ), regardless of the positioning of server cartridges  108  and power supply modules  200 . 
     FIG. 4 is a side view illustrating a simplified representation of major internal components of a server cartridge  108  according to one embodiment of the present invention. In FIG. 4, the metal box encasing server cartridge  108  has been removed to illustrate the internal components. Server cartridge  108  includes hard disk drive  400 , dual in-line memory modules (DIMMs)  402 , processor board  404 , LAN circuitry  406 , PCI slot  408 , circuit board  410 , and connector  306 . DIMMs  402  and hard disk drive  400  are mounted on processor board  404 . Processor board  404 , LAN circuitry  406 , PCI slot  408 , and connector  306  are mounted on circuit board  410 . In one embodiment, processor board  404  includes processor  600  (shown in FIG.  6 ), and a heat sink (not shown). In one form of the invention, hard disk drive  400  is a dual hard disk drive for redundancy. 
     FIG. 5 is a front view illustrating a simplified representation of major internal components of a server cartridge  108  according to one embodiment of the present invention. As shown in FIG. 5, PCI card  500  is inserted in PCI slot  408 . In one embodiment, PCI card  500  is a 1000 Base T LAN card and is coupled to LAN port  112  (shown in FIG.  1 ). In one form of the invention, LAN circuitry  406  is configured for a 100 Base T LAN, and is coupled to LAN port  114  (shown in FIG.  1 ). In one embodiment, connector  306  includes connections for power and a management bus. 
     FIG. 6 is an electrical block diagram illustrating major components of a server cartridge  108  according to one embodiment of the present invention. Server cartridge  108  includes memory  402 , processor  600 , hard disk drive  400 , USB link  602 , PCI bus  604 , and LAN link  606 . In one embodiment, memory  402  includes 2 double data rate (DDR) ECC memory modules. In one embodiment, USB link  602  is used for debugging of server cartridge  108 . In one form of the invention, hard disk drive  400  is coupled to processor  600  by a SCSI link. Processor  600  is coupled to PCI slot  408  (shown in FIGS. 4 and 5) via PCI bus  604 , and communicates with PCI card  500  over PCI bus  604 . Processor  600  is coupled to LAN circuitry  406  (shown in FIGS. 4 and 5) by LAN link  606  for communication with a LAN. In one form of the invention, processor  600  is a dual processor for redundancy. In one embodiment, LAN link  606  is also coupled to connector  306  (shown in FIG. 4) and is used for server management functions. 
     In one form of the invention, processor  600  is Intel IA-32 compatible, and server cartridges  108  use a Windows 2000 or Linux operating system with standard input/output drivers. In one embodiment, server cartridges  108  use standard PC server components, such as ECC memory, SCSI hard drives, PCI cards, chipsets, connectors, and other components. 
     Embodiments of the present invention provide a high server density, with high reliability, and faster server installation and removal times than current systems. In one embodiment, an entire server can be replaced in less than one minute. Embodiments of the present invention have an effective size of less than 0.5U. Embodiments of the present invention are particularly useful in server farm applications where hundreds or thousands of servers are required at one site. 
     Embodiments of the present invention provide efficient cooling for higher power, next generation CPU&#39;s, and a minimized number of electrical connector contacts, which translates into higher reliability. In one embodiment, server cartridges  108  and cartridge cage  106  do not contain any interconnect cables, which increases system reliability. 
     Embodiments of the present invention provide approximately twice the server density of existing board server systems, and have a more robust package, and less stringent alignment requirements than existing board server systems. Unlike board server systems, handling of server cartridges  108  in embodiments of the present invention will not induce ESD failures. Further, swapping of server cartridges  108  in embodiments of the present invention can be performed by a robot or other automated control system that can traverse the front or the rear of a large rack, which is not practical with board servers. 
     Although specific embodiments have been illustrated and described herein for purposes of description of the preferred embodiment, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. Those with skill in the chemical, mechanical, electromechanical, electrical, and computer arts will readily appreciate that the present invention may be implemented in a very wide variety of embodiments. This application is intended to cover any adaptations or variations of the preferred embodiments discussed herein. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.