Patent Application
20070088816
The present disclosure relates generally to computer systems and information handling systems, and, more particularly, to a system and method for monitoring the status of a bus in a server environment.
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 these users is an information handling system. 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 vary with respect to the type of information handled; the methods for handling the information; the methods for processing, storing or communicating the information; the amount of information processed, stored, or communicated; and the speed and efficiency with which the information is 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 or comprise 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.
A computer system, such as a server computer, may include a network interface controller that is communicatively coupled to microcontroller that resides on the motherboard of the server computer. The on-board microcontroller is sometimes referred to as a baseboard management controller. The baseboard management controller serves as a centralized processor for hardware-level management of the server computer. The baseboard management controller may be coupled to other physical elements of the server computer, including, for example, the remote access card, card temperature sensors, network interface card, and a power supply. The baseboard management controller may be coupled to these other devices by a bus between the two devices.
In accordance with the present disclosure, a system and method is disclosed in which the buses of a server computer are monitored through server management software. A data structure for a monitored bus or group of buses is created and stored in a repository of data structures for other monitored devices within the server computer. As events, such as failure events, occur on one or more of the monitored buses, the event is recorded in an event log. Using the server management software, monitoring commands can be issued by the baseboard management controller to each monitored bus to check the status of the bus.
The system and method disclosed herein is technically advantageous because it provides a technique for the remote monitoring of buses, including I2C buses, in the interior of a server computer. Through the use of the system and method disclosed herein, buses within the interior of a server computer can be monitored and the status of those buses can be reported, despite the loss of operating power to the server computer. Another technical advantage of the system and method disclosed herein is that the system and method disclosed herein employs the Intelligent Platform Management Interface (IPMI). A sensor is established in accordance with the IPMI specification for each of the I2C buses of the server computer. Once a data record for this sensor is established in the SDR repository, the status of each I2C bus in the server computer can be monitored using the established IPMI protocol. Other technical advantages will be apparent to those of ordinary skill in the art in view of the following specification, claims, and drawings.
A more complete understanding of the present embodiments and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features, and wherein:
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 communication 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 system and method disclosed herein concerns a technique for monitoring and reporting the status of buses, including I2C buses, within a server computer. In the hardware configuration of a server computer, a baseboard management controller may be coupled through I2C bus lines to other physical elements of the server computer. These other physical elements may include, for example, the network interface controller, the remote access card, temperature sensors, and a power supply. Using a management interface, such as the Intelligent Platform Management Interface (IPMI), a protocol and software tool is established to monitor the status of the I2C buses in the server computer, including the I2C buses coupled to the baseboard management controller.
Shown in
In server computer 10, buses, such as I2C buses, are coupled between the baseboard management controller and some of the hardware elements of the server system. An I2C bus, labeled as I2C Bus 0, is coupled between the backplane 34, remote access card 26, and baseboard management controller 20. A second I2C bus, labeled I2C bus 1, is coupled between the baseboard management controller 20 and network interface controller 16. Another I2C bus, labeled in
Nonvolatile storage 28 includes a SDR repository 28 and a system event log 30. Sensor data records (SDR) repository 32 is a centralized, non-volatile storage location within the server computer. The SDR repository is managed by and can be accessed by the baseboard management controller. Stored in SDR repository are sensor data records, which comprise information and specifications for each sensor in the server computer. The SDR repository provides the server management software of the computer system with a data entry that describes the number, type, and configuration of each sensor of the server system. As an example, in the case of a temperature sensor, the SDR entry for the temperature sensor may include the parameters of the temperature sensor and any threshold operating values for the temperature sensor. Similarly, in the case of a bus sensor, the SDR entry would specify the error conditions of the bus that are monitored by the baseboard management controller. These error conditions could include arbitration errors, no stop conditions, lines stuck low, and the recovery policy of the bus. System event log 30 is a nonvolatile storage area that is a log of events that have been recognized by the server management software of the server system. As events occur, the server management software records those events in the system event log 30. An entry in the system event log will include, at a minimum, an identification of the sensor and the event experienced by the sensor.
One example of server management software is IPMI software. The IPMI protocol defines a set of established interfaces for the monitoring and reporting the status of components of a server computer. IPMI software is server management software that executes on the baseboard management controller. IPMI software employs the intelligence of the various hardware devices to present a common, standardized interface for monitoring and reporting on the status of the hardware devices within the server system. The IPMI protocol was established, in part, by Dell Inc. of Round Rock, Tex.; Hewlett-Packard Company of Palo Alto, Calif.; Intel Corporation of Santa Clara, Calif.; and NEC Corporation of Tokyo, Japan. The specification for the IPMI protocol can be found on the Intel web site at http://www.intel .com/design/servers/ipmi.
The system and method disclosed herein involves defining an IPMI bus sensor for each of the buses of the server system. The data record for each I2C bus sensor is saved to the SDR repository 32, and each bus is defined to the server management software as having the characteristics of a sensor. Once each I2C bus sensor is entered in the SDR repository, the IPMI software executing on the baseboard management controller causes the controller to monitor and identify various bus errors or conditions present in the I2C buses, including arbitration errors, traffic errors, and the existence of data or clock lines that are stuck at a logical low. As defined events occur on one or more of the I2C buses, the baseboard management controller records these events in the system event log.
In operation, a client on the network 14 can issue an IPMI “get” command to evaluate the status of one or more of the I2C buses of the server computer. As an example an IPMI get command for I2C Bus 0 maybe the command:
Get Sensor Reading (I2C Bus 0)
The result of this command is a list of status values for the I2C Bus. This result is returned to the client that issued the get command or displayed in a monitor associated with the server computer. Shown in
As an alternative to reporting the status of an I2C bus in the server computer in response to an IPMI command issued by a client computer, the status of the I2C bus could be monitored continuously for bus errors. Shown in
Because the baseboard management controller and the nonvolatile memory storage area of the SDR repository and system event log are separately powered, the system and method described herein can operate despite the loss of power to the remainder of the server computer. As a result, the status of the I2C buses of the server computer can be monitored despite the loss of operational power to the server computer.
The bus monitoring system of this disclosure has been described with reference to an implementation in which a data structure is established for each bus. Instead of establish a data structure for each bus, a single data structure could be established that represents the status of a group of buses. It should also be recognized that the system and method disclosed herein is not limited in its application to the IPMI specification or I2C buses. Rather, the system and method disclosed herein may be employed with any system management software to monitor any buses within a server computer. Although the present disclosure 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 the scope of the invention as defined by the appended claims.
