System and method for blade information handling system power inventory

[0001] 1. Field of the Invention

[0002] The present invention relates in general to the field of information handling system power management, and more particularly to a system and method for blade information handling system power inventory in a reduced power consumption state.

[0003] 2. Description of the Related Art

[0004] 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.

[0005] Often, especially with larger enterprises, large numbers of information handling servers perform functions critical to enterprise success, such as interfacing with customers or coordinating enterprise operations. Enterprises typically have difficulty placing large numbers of server information handling systems in a common location due to the physical footprint of the systems as well as power and cooling constraints. One solution increasingly selected by enterprises is the installation of blade servers. A blade server generally has a chassis with slots sized to accept ten or more blade information handling system. Each blade information handling system is essentially a motherboard with a processor, storage and network interfaces that engage in the blade server chassis slot; however, the blade information handling systems share common support resources, such as power and cooling resources. The use of a single set of power and cooling resources in a chassis reduces the footprint of the chassis. Further footprint efficiencies are gained by the use of a single housing instead of a separate housing for each blade. A chassis management controller (CMC) manages the chassis-level subsystems while a baseboard management controller (BMC) on each blade manages the physical operation of the blade, such temperature sensors and application of power. Remote management through the CMC and BMC are available through in band and out of band communication.

[0006] One difficulty associated with blade servers is ensuring that the power available through a blade chassis is sufficient for all blade information handling systems that are loaded in the chassis. A typical blade chassis has a longevity of five or more years. Over the time that a blade chassis is deployed, empty slots are sometimes filled and existing blade information handling systems are sometimes replaced with new blades or upgraded with new components. Often, newer information handling systems and components have greater power needs than older components. To avoid overburdening a blade chassis power supply, an estimated power consumption of blade information handling systems is applied that will minimize disruption in operations. Typically, a power consumption inventory is made at power up of each blade information handling system. However, if the blade chassis has an upgraded, replaced or new blade information handling system then powering up the blade information handling system to take the power inventory can cause the blade chassis to exceed its power capacity.

[0007] Therefore a need has arisen for a system and method which estimates blade information handling system power consumption before power up.

[0008] In accordance with the present invention, a system and method are provided which substantially reduce the disadvantages and problems associated with previous methods and systems for estimating blade information handling system power consumption. A preliminary power consumption inventory is performed before startup of a blade information handling system to confirm that adequate blade chassis power is available to support operation of the blade information handling system. A final power consumption inventory is performed after startup of the blade information handling system to provide a more accurate basis for determining whether adequate chassis power exists to support subsequent startups of other blade information handling systems in the chassis.

[0009] More specifically, a blade information handling system server chassis supports operation of plural blade information handling systems with a common power source managed by a chassis management controller. A baseboard management controller on each blade information handling system performs a preliminary power inventory of processing components of the blade information handling system with the processing components in an off state. The preliminary power consumption inventory is communicated to the chassis management controller to obtain authorization for startup. After startup of the blade information handling system, a final power consumption inventory is performed with the blade information handling system processing components in an on state. The final power consumption inventory is communicated to the chassis management controller for use in determinations of whether to authorize subsequent startups of other blade information handling systems at the chassis. Since authorization for startup based is more likely on the final versus the preliminary power consumption inventories, if authorization to startup is denied to a blade information handling system, another startup request is communicated by the blade information handling system after a predetermined timeout.

[0010] The present invention provides a number of important technical advantages. One example of an important technical advantage is that an estimate of power consumption by a blade information handling system is performed with the BMC in a minimal power consumption state, thus reducing the risk that the power capacity of the blade chassis will be inadvertently exceeded. A basic power consumption estimate is available even for upgraded or new blade information handling systems without powering up the processing components on the blade information handling system. A “worst case” estimate made by the BMC with processing components inactive allows blade start-up for a subsequent fine tuned power consumption determination with the blade processing components in an operating state.

[0015] A blade information handling system server applies a preliminary power inventory performed with processing components in an off state to avoid excess power demand on startup and a final power inventory with processing components in an on state to ensure full use of power resources. 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 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.

[0016] Referring now to FIG. 1, a block diagram depicts a blade information handling system server 10 using dual power consumption inventories to manage power. Blade information handling system server 10 has plural blade information handling systems 12 disposed in blade slots 14 of a chassis 16. A common power subsystem 18 and cooling subsystem 20 support blade information handling systems 12 through slots 14 under the management of a chassis management controller 22. Blade information handling systems 12 have plural processing components to process information, such as one or more CPUs 24, RAM 26, one or more hard disk drives 30 and a chipset 32. A baseboard management controller 34 associated with each blade information handling system 12 manages system operations and interactions with chassis management controller 22. For instance, remote out of band control over each blade information handling system 12 is supported through communications of chassis management controller 22 and baseboard management controller 34. Each baseboard management controller 22 starts up and shuts off its associated blade information handling system 12 based on authorization from chassis management controller 22.

[0017] In order to avoid excess power consumption by the startup of a blade information handling system 12, a power inventory module 36 performs power consumption inventories and communicates the power consumption inventories to chassis management controller 22. Chassis management controller 22 applies the power consumption inventories communicated by each blade information handling system 12 to authorize or deny requests to startup. An inactive power estimator 38 performs the preliminary power consumption inventory with the processing components of its blade information handling system 12 in an off state. This first power consumption inventory provides an estimate of the greatest expected power consumption based upon incomplete information retrievable by baseboard management controller 34 with the processing components in the off state. If the chassis has power available to support operations within the first power consumption inventory, then chassis management controller 22 authorizes startup. After startup, an active power estimator 40 performs a final power consumption inventory with the processing components of its blade information handling system 12 in an on state. This second power consumption inventory provides a more complete estimate of the greatest expected power consumption based upon information retrievable by baseboard management controller 34 with the processing components in the on state. The more accurate final power consumption inventory, which generally is less than the preliminary power consumption inventory, is used by chassis management controller 22 to determine power available for subsequent startup requests.

[0018] Because a blade information handling system server 10 may have multiple blade information handling systems 12, a difficulty might arise if plural preliminary power inventories are sent in synch to chassis management controller 22. For instance, available power will appear less based on preliminary power inventories so that a blade information handling system may be denied authorization to startup when, in fact, adequate chassis power will be available after the final power inventories are reported. A delay module 42 responds to a denial of a request to startup from chassis management controller 22 by setting a predetermined timeout and then re-communicating the request to startup with the preliminary power inventory to chassis management controller 22. If, during the timeout, another blade information handling system 12 reported a final power consumption inventory that increased the available chassis power enough, then chassis management controller 22 will approve the startup request. Another difficulty that can arise is that firmware corruption within 34 baseboard management controller might prevent the performance of the preliminary power consumption inventory. A firmware verification module 44 analyzes the firmware for corruption, such as might occur if a firmware update was only partially completed. If the firmware is corrupted, a worst case power consumption inventory value is provided to chassis management controller 22. Once startup of the blade information handling system is approved, the corrupt firmware is corrected.

[0019] Referring now to FIG. 2, a flow diagram depicts a process for performing a power inventory with processing components in an off state. The process starts at step 46 and proceeds to step 48 for power up of the blade baseboard management controller. At step 50, pre-start checks are performed to prepare for blade startup, such as checking the AC recovery mode, wake on LAN, real time clock wake, whether a manual button press initiated startup, and whether a remote IPMI request initiated startup. Generally, the baseboard management controller receives power and automatically turns on if power is applied to the blade server chassis. With a blade information handling system's baseboard management controller on and the processing components off, the power draw from the blade is at a minimal value. Performing the power inventory depends upon proper operation of power inventory firmware running on the baseboard management controller. At step 52 a determination is made of whether the firmware is corrupt at POST of the baseboard management controller and, if so the process continues to step 54 without performing a power consumption inventory. At step 54 a predetermined worst case power consumption inventory value is assigned and the process continues to step 56 to request a power-up authorization from the chassis management controller. If authorization to startup is approved, the firmware is updated with in band communication, and if authorization is denied then the firmware is updates with slower out of band communication.

[0020] If at step 52 the firmware is not corrupt, the process continues to step 58 to inventory the CPUs of the blade information handling system. With only the baseboard management controller powered, only the presence or absence of CPUs can be detected, so the baseboard management controller detects the number of CPUs and multiplies the detected number against a worst case power consumption number per CPU per type of blade information handling system. At step 60, memory is inventoried through interaction with the memory SPD to obtain DIMM vendor and size. DIMM vendor and size information available with the memory in an off state provides a basis for achieving an accurate power consumption estimate. At step 62, fabric mezzanines are inventoried by counting the number present and applying a nominal power consumption value, such as 15 Watts. Since fabric mezzanine power consumption is minimal, inventory of presence provides an adequate power consumption estimate. At step 64, option cards are detected, such as SAS IOC modules and inventoried by presence. At step 66, a value is retrieved for the planar power consumption at the blade mother board level, including a value for each hard disk drive that is present. At step 68, the power consumption of the processing components is compiled to provide a preliminary power consumption inventory. At step 70 the preliminary power consumption inventory is provided to the chassis management controller so that, at step 56, the process can continue to request a power-up authorization for the blade information handling system.

[0021] Referring now to FIG. 3, a flow diagram depicts a process for performing a power inventory with processing components in an on state. The process begins at step 72 with a determination at the chassis management controller of whether sufficient power exists at the chassis to support startup of the blade information handling system. For instance, the chassis management controller subtracts the power inventories of blades in an on state from the available chassis power and authorizes startup if the blades' preliminary power inventory is less than the available power. If sufficient power is not present to authorize startup, the process continues to step 74 to enter a predetermined time delay and then to step 76 to again request authorization for startup. The time delay offers an opportunity for other blades in the startup process to complete a final power consumption inventory and provide that value to the chassis management controller. Based on a reduction for the final power consumption inventory relative to the preliminary power consumption inventory for other blades in the startup process, the chassis management controller may have adequate chassis power available to authorize startup. If not, the process ends at step 78 with the blade idle until another power on event occurs.

[0022] If at step 72 the chassis management controller authorizes startup, the process continues to step 80 at which the baseboard management controller initiates startup of its associated blade. At step 82, the CPUs are inventoried in an on state for type and speed, which allows a more accurate estimate of maximum power consumption. The CPU power consumption inventory in the on state should reduce the final power consumption inventory since a worst case value is used to estimate CPU power consumption in the off state for the preliminary power consumption inventory. At step 84, the power consumption inventory is re-compiled with the updated CPU power consumption estimate and, at step 86, the final power consumption inventory value is provided to the chassis management controller. At step 88, the blade information handling system enters an operational state with the chassis management controller having the final power consumption inventory on which to base determinations for subsequent blade information handling system startup requests.

[0023] Although the present invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims.