Abstract:
Systems and methods for a blade server to obtain the blade type and configuration of the chassis without requiring the blades to be fully powered. Using this method the user has the ability to acquire correct inventory and slot status of the chassis through the use of a low power auxiliary power state. The user is then able to apply the proper power budgeting and thermal algorithm requirements utilizing this information while minimizing the power consumption necessary to acquire such information. In addition, an intelligent search algorithm may be utilized to scan the blades for blade information thus further minimizing power consumption and decreasing the time needed to inventory the blades.

Description:
TECHNICAL FIELD 
     This invention relates to the operation of blades within blade servers and, more particularly, to the identification and configuration of blades within a blade server chassis. 
     BACKGROUND 
     As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems. 
     Some information handling systems are implemented as multiple processing components configured as part of a single system. A “blade” is a general term often used to refer to one component in a system that is designed to accept some number of components. Blades can be, for example, individual servers that plug into a single cabinet or chassis or individual port cards that add connectivity to a switch. Blades are often hot swappable hardware devices. A “blade server” is a general term often used to refer to system architecture those houses multiple server modules or blades in a single chassis. Blade servers are widely used, for example, in data centers to save space and improve system management. Either self-standing or rack mounted, the chassis provides the power supply, and each blade often may have its own CPU, memory and hard disk. Redundant power supplies may also be provided. Blade servers generally provide their own management systems and may include a network or storage switch or other components. With enterprise-class blade servers, disk storage is often external, and the blades are diskless. This approach allows for more efficient fail-over techniques because applications are not tied to specific hardware and a particular instance of the operating system. In such a solution, the blades are typically anonymous and interchangeable. 
     In the modular server market, there are a variety of blade types that service various market segments including small general purpose, double high, double wide and quad blades (which are double high and double wide). These various blade types may occupy one or more slots in a chassis. The actual number of blades in a chassis is dependent upon the type of blades. Also, the different blade types can be inserted in any combination in the modular server chassis, for example, a 2×8 (double high and eight wide) slot chassis. In the prior art, the blade hardware typically only relays to the chassis controller blade presence and power state. The chassis controller displays the inventory and blade slot population status based on this signal alone. Any time the blade power of the chassis is generally powered OFF, in this case meaning that the blades are not powered but that the chassis controller board may still be powered for other chassis controller functionality, the chassis controller has no method to determine the type of the blade. The chassis controller then reports each consumed slot as a separate independent entity, even for multi-slot blades which have a primary/master slot in which all control is achieved and one or more secondary/slave slots. This erroneous information causes incorrect inventory and a lack of ability to communicate with the hypothetical blades. This problem can only be corrected by turning the chassis blade power fully ON. This creates customer dissatisfaction because blade type recognition and configuration is dependent on the chassis blade power state, which consumes excess power and generates excess heat. 
     SUMMARY 
     The present disclosure provides systems and methods for a blade server to obtain the blade type and configuration of the chassis without requiring the blades to be fully powered. Using this method the use has the ability to acquire correct inventory and slot status of the chassis through the use of a low power auxiliary power state. The user is then able to apply the proper power budgeting and thermal algorithm requirements utilizing this information while minimizing the power consumption necessary to acquire such information. In addition, an intelligent search algorithm may be utilized to scan the blades for blade information thus further minimizing power consumption and decreasing the time needed to inventory the blades. 
     In one embodiment, the present disclosure provides methods for minimizing blade power ON time during the chassis controller scan technique. By reducing the full blade chassis power ON time during the probe of the blade chassis, the customer is able to also reduce excess power consumption and heat generated. This blade scan technique is achieved utilizing a low power handshake. The scan technique performs a blade-by-blade inventory of the entire chassis in order to determine the chassis pre-power inventory. As described below, other features and variations can be implemented, if desired, and related systems can be utilized, as well. 
     In another embodiment, the techniques disclosed within allows the chassis controller to differentiate between a low-level blade probing inventory and a normal full blade chassis power on event, so that the chassis controller is able to hold the system from booting up. By preventing the system from booting up, power consumption is minimized. As described below, other features and variations can be implemented, if desired, and related systems can be utilized, as well. 
     In another embodiment, a method of inventorying the blades of a blade chassis is provided. The method may include providing low power auxiliary power to at least a first blade within the blade chassis, the low power auxiliary power being less than the normal power utilized to operate the blade. The method may further include selectively powering a portion of the blade in a low power state, the portion of the first blade being sufficient to communicate information regarding the first blade to at least one chassis system component. The method may further include communicating the first blade information to the at least one chassis system component while the low power auxiliary power is provided to the first blade. 
     In still another embodiment a method of operating an information handling system which comprises a plurality of blade components and a chassis controller is provided. This method may include obtaining pre-set information handling system limitations and providing low power auxiliary power to the plurality of blade components within the information handling system. The method may further include selectively powering only a portion of the component in a low power state, the portion of the component being sufficient to communicate information regarding the first component to a chassis controller, and communicating the first component information to the chassis controller while the low power auxiliary power is provided to the first blade. The method further includes scanning a plurality of the blades component while low power auxiliary power is provided to the plurality of blade components to identify blade information and selectively bypassing the scanning of at least one of the blade components of the information handling system based upon the information regarding the information handling system limitations. 
     In yet another embodiment, an information handling system is provided. The system includes a blade server chassis and a chassis controller within the blade server chassis. The system further includes a plurality of server blades coupled to the chassis controller, the server blades having a low power mode to operate the blade under less than normal power, the low power mode providing power to components of the blade sufficient to provide blade configuration information to the chassis controller. In the system, the configuration information allows the chassis controller to identify and inventory the server blades present in the blade server chassis. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       It is noted that the appended drawings illustrate only exemplary embodiments of the techniques described herein and are, therefore, not to be considered limiting of its scope, for the techniques may admit to other equally effective embodiments. 
         FIG. 1  is a block diagram for a blade array chassis including a chassis controller and a power supply. 
         FIG. 2  is an example of a mixed blade size configuration in a blade chassis. 
         FIG. 3  is a diagram of a blade size scanning support hardware. 
         FIG. 4  is a flow diagram for blade type inventory procedure in a blade chassis. 
     
    
    
     DETAILED DESCRIPTION 
     For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system may be a personal computer, a server computer system, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components. 
     The present disclosure provides a solution to obtain blade type and blade configuration regardless of the main chassis power state. This solution provides the customer with correct inventory, slot status and it also invokes the proper power budgeting and thermal algorithm requirements. The chassis controller utilizes a scan technique to probe the blades for the blade information. The information provided by the blade may include blade type, size, configuration, number of CPUs and/or other information. It will be recognized that the concepts disclosed herein are not limited to any particular type of status information communicated to the chassis controller by the blade. This pre-chassis inventory is an important benefit to customers, by preventing potential issues such as not allocating enough Power Supply Units (PSU) for the blade chassis. 
       FIG. 1  is a block diagram for a blade array chassis  100 , which is comprised of a chassis controller  102 , a plurality of blades  106 A,  106 B . . .  106 (N), and a power supply  104 . The chassis  100  can be configured to accept a plurality of blades, as represented by BLADE 1   106 A, BLADE 2   106 B . . . BLADE (N)  106 (N). In addition to the chassis controller  102 , the chassis  100  can include a chassis power supply  104  that is coupled to the chassis controller  102  utilizing power supply line  114 . The chassis controller  102  utilizes control line  112  to exercise power supply  104  ON/OFF. As depicted, power is provided to the blades  106 A,  106 B,  106 C . . .  106 (N) from the power supply utilizing connection  108 . The chassis controller  102  can communicate with the blades  106 A,  106 B  106 C . . .  106 (N) through the communication channel  110 . It is noted that any of the blades  106 A,  106 B . . .  106 (N) can be implemented using a wide variety of architectures and configurations. 
       FIG. 2  is an example of a mixed blade size configuration in a 2×8 slot modular server chassis  200 . In this configuration there are two rows of eight slots. The chassis  200  is further divided into four quad walls, denoted by the bold boundary lines. The chassis limitations include that a master in a multi-slot blade is always in the upper location of a double high blade or upper-left location of a quad wall for a quad blade. Also, the multi-slot blades may not cross the quad walls. In the example, blade locations  1  and  8  have master blades  202  while blade locations  5 ,  6 ,  9  and  16  are empty blade locations  204 . The blade location  2  is occupied by the master  206  of a double height blade, whose slave  208  is located in blade location  10 . Similarly, blade locations  7  and  15  represent another double height blade. The blade location  3  is occupied by the master  214  of a quad master blade and the corresponding quad slaves  216  occupy blade locations  4 ,  11  and  12 . The blade location  13  is occupied by the master  210  of a doublewide blade and the corresponding slave  212  of the doublewide blade resides in location  14 . The chassis  200 , as shown, is just one exemplary configuration of blades in a chassis. It will be recognized that the concepts described herein could be used with any size chassis. As such, the term chassis is not limited to the particular configuration shown. In addition, master-slave combinations of blades are not limited to double high, double wide or quad configurations, but rather any type of desired combination could be used. 
     An example blade slot scan order may be described with reference to  FIG. 2 .  FIG. 2  is an example of a mixed blade size configuration in a blade chassis where the exemplary blade scan order may be: (step  1 ) blade location  1  is detected as a single master, (step  2 ) blade location  2  is detected as a double high master, (step  3 ) blade location  3  is detected as a quad master, (step  4 ) blade location  4  is skipped as part of slot  3 , (steps  5  and  6 ) blade locations  5  and  6  are empty with no active probe, (step  7 ) blade location  7  is detected as a double high master, (step  8 ) blade location  8  is detected as a single master, (step  9 ) blade location  9  is empty with no active probe, (step  10 ) blade location  10  is skipped as part of slot  2 , (steps  11  and  12 ) blade locations  11  and  12  are skipped as part of slot  3 , (step  13 ) blade location  13  is detected as a double wide master, (step  14 ) blade location  14  is skipped as part of slot  13 , (step  15 ) blade location  15  is skipped as part of slot  7  and (step  16 ) blade location  16  is empty with no active probe. In the example embodiment  200  depicted, it should be noted that there are blade chassis limitations. One being that multi-slot blades may not cross-bold quad walls. Another limitation being that a master in a multi-slot blade is always in the upper-left blade location within a quad wall. Other blade chassis limitations may exist and those shown herein are exemplary. The technique described herein may allow the pre-existing knowledge of the blade chassis limitations and possible configurations to be utilized in order to more efficiently scan the chassis. Such as, for example, scan certain slots first and/or skipping certain slots. 
     In the present disclosure, full blade power to the blade chassis is not essential in order to inventory blade type and blade configuration. When full blade power to the blade chassis is turned ON, a typical system may utilize on the order of 375 watts for a single height chassis and 600 watts for a double height chassis. However, as disclosed herein, a low power auxiliary mode may be utilized to inventory the blade chassis. In the auxiliary mode disclosed herein, only approximately 12.5 watts of power is necessary to power the chassis controller to perform the inventory of the blade chassis and other chassis non-blade hardware tasks (25 watts is redundant chassis controllers are used). Only one watt of power is needed per blade to inventory a blade chassis with sixteen slots. In one embodiment, the chassis controller  102  may provide control signals such that the power supply supplies auxiliary power to the blades, one blade at a time, utilizing a low power handshake before turning the blade back OFF. Thus using the incremental scanning technique described herein in which only one blade is active at a time, only 13.5 watts of power are consumed by the blades at any given time to perform the inventory task. 
       FIG. 3  is a diagram of a blade size scanning support hardware  300 , which allows the chassis controller  102  to selectively take blade inventory using a low power handshake. When low power auxiliary power  108  is applied to the blade  106 A, the blades&#39; complex programmable logic device (CPLD)  302  initializes and begins to transmit inventory information. The blade complex programmable logic device  302  holds the auxiliary logic in rest and holds the main powered logic unpowered to prevent booting and minimize power consumption. The blade complex programmable logic device  302  then transmits blade size inventory to the chassis controller  102  through bus  110 . In one exemplary embodiment bus  110  may be time division multiplex shifty serial bus. The bus  110  may communicate between the CPLD and a time division multiplexer controller within the chassis controller. In the exemplary embodiment the bus  110  may be a bus that is typically available in prior art systems for providing out of band low level communication interfaces for various system communications such as alerts, power down, or other hardware control features. In this manner a hardware control status bus may also be utilized during low power operations to provide blade information to the chassis controller. 
     When low power auxiliary power is provided to the blade, the CPLD initializes and begins participating in the bus  110  to provide information to the chassis controller. In this manner, minimal logic is powered up by the auxiliary power and this minimal logic is utilized to power sufficient operations to provide blade configuration and status information to the chassis controller. The chassis controller  102  gets interrupted by the communication bus  110  and registers the blade geometry and configuration provided from the blade. The chassis controller  102  then turns the auxiliary power OFF to the blade slot and moves on to the next appropriate slot, thereby scanning the entire chassis and determining the pre chassis power inventory. 
     In  FIG. 3 , the blade size scanning support hardware  300  is utilized to inventory blade type. In this present disclosure, the chassis controller  102  initiates the blade type probe under certain circumstances. For example, blade type probe is instated when power to the blade chassis is first turned ON and the chassis controller  102  boots up. Probing may also be initiated when the blade chassis is in a state in which the blade power is OFF and a blade is detected as inserted. In such a case, only the inserted blade slot(s) need to be scanned again. Also, the blade type probe may be initiated when the chassis controller  102  becomes active as a result of a chassis controller reset. Blade type probing may occur at other times and the examples given herein are not meant to be limiting. 
       FIG. 4  is a detailed flow diagram for blade type inventory in a blade chassis. In the embodiment  400  depicted, it is assumed that a blade server chassis  100  is configured to accept a maximum of N blades total. The process flow begins with block  402 , where the chassis controller boots up and determines if the blade power of the chassis is ON or OFF. If it is determined that the blade power of the chassis  100  is ON, as in block  404 , then the flow moves to block  406  where the chassis controller  102  scans the blade chassis for blade presence. Then the flow proceeds down to decision block  408 , where it is determined if a blade is present in the slot. If the answer to block  408  is “NO”, then the flow moves back up to block  406  where the chassis controller  102  scans the blade chassis for blade presence again. If the answer to block  408  is “YES”, then the flow proceeds to block  410 , where the chassis controller reads the blade type from the blade. The flow then moves back up to block  406 , where the chassis controller  102  scans the blade chassis for blade presence and the procedure is repeated again until all blades are read. 
     When the chassis controller boots up in block  402  and it is determined that the blade power of chassis  100  is OFF, as in block  418 , then flow proceeds in the following manner. The flow passes on to block  420  where the chassis controller  102  provides auxiliary power to slot (N) in the blade chassis. In decision block  422 , determination is made if a blade is present in the slot. If the answer in block  422  is “NO”, then the flow passes down to decision block  432 . If the answer in block  422  is “YES”, then the flow moves on to block  424  where the blade complex programmable logic device  302  initializes and reads the blade size bits. In block  426 , the blade complex programmable logic device  302  writes the bits in the time division multiplex shifty register of the chassis controller using the communication bus  110 . The flow then passes on to block  428  where the chassis controller  102  reads the time division multiplex shifty register and determines the blade type. In block  430 , the position is incremented to the next slot. In decision block  432 , it is determined whether a slave occupies the slot. If the answer to block  432  is “YES”, then the flows back up to block  430  where the slot is incremented. If the answer is “NO” to block  432 , then the flow moves back up to block  420  and the procedure is repeated again. 
     Independent of whether the chassis controller detects blade power on or blade power off, the blade inventory process may account for the detection of an insertion of a blade. In the case where the chassis controller has booted up in block  402  blade insertion is monitored in decision block  412 , where the chassis controller  102  determines if a blade is inserted in the slot. If the answer in block  412  is “NO”, then the chassis controller status remains at block  412  awaiting for a blade insertion event. If the answer in block  412  is “YES”, then the flow passes to block  414  where the chassis controller  102  detects a presence signal from the blade slot. In decision block  416 , a determination is made whether the blade power of the chassis is powered on. If the answer in block  416  is “YES”, then the flow passes to block  410  where the chassis controller reads the blade type from the blade and follows the process flow. If the answer in block  416  is “NO”, then the flow passes on to block  420  where the chassis controller  102  provides auxiliary power to newly inserted slot in the blade chassis and follows the process flow. 
     Further modifications and alternative embodiments of the techniques described herein will be apparent to those skilled in the art in view of this description. It will be recognized, therefore, that the techniques described herein are not limited by these example arrangements. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the manner of carrying out the techniques described herein. It is to be understood that the forms of the techniques described herein shown and described are to be taken as the presently preferred embodiments. Various changes may be made in the implementations and architectures. For example, equivalent elements may be substituted for those illustrated and described herein and certain features of the techniques described herein may be utilized independently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the techniques.