Intelligent Platform Management Interface
Encyclopedia
The Intelligent Platform Management Interface (IPMI) is a standardized
computer system interface
used by system administrator
s to manage a computer system and monitor its operation.
The development of this interface specification was led by Intel Corporation and is supported by more than two hundred computer systems vendors. Dell
, Hewlett-Packard
, Intel, and NEC Corporation announced IPMI v1.0 on 1998-09-16, v1.5 on 2001-03-01, and v2.0 on 2004-02-14.
and allows administrators to manage a system remotely in the absence of an operating system or of the system management
software. The monitored system may be powered off, but must be connected to a power source and the monitoring medium, typically a local area network
connection. IPMI can also function after the operating system has started, and exposes management data and structures to the system management software. IPMI prescribes only the structure and format of the interfaces as a standard, while detailed implementations may vary.
An implementation of IPMI version 1.5 can communicate via a direct serial
connection or via a side-band local area network
(LAN) connection to a remote client
. The side-band LAN connection utilizes the board network interface controller (NIC). This solution is less expensive than a dedicated LAN connection but also has limited bandwidth. Systems compliant with IPMI version 2.0 can also communicate via serial over LAN
. System administrators can then use IPMI messaging to query platform status, to review hardware logs, or to issue other requests from a remote console through the same connections. The standard also defines an alerting mechanism for the system to send a simple network management protocol
(SNMP) platform event trap (PET).
(SMBUS) interface between the BMC (Baseboard Management Controller) and the board Network Interface Controller (NIC). This solution has the advantage of reduced costs but also provides limited bandwidth – sufficient for text console redirection but not for video redirection. For example, when a remote computer is down the system administrator can access it through IPMI and utilize a text console. This will be sufficient for a few vital functions, such as checking the event log, accessing the BIOS setup and perform power on, power off or power cycle. However, more advanced functions, such as remote re-installation of an operating system, may require an out-of-band management
approach utilizing a dedicated LAN Connection.
(Inter-Integrated Circuit). The BMC connects to satellite controllers or another BMC in another chassis via the Intelligent Platform Management Controller (IPMC) bus or bridge. It may be managed with the Remote Management Control Protocol (RMCP), a specialized wire protocol defined by this specification.
Several vendors develop and market BMC chips. A BMC utilized for embedded applications may have limited memory and require optimized firmware code for implementation of the full IPMI functionality. Highly integrated BMCs can provide complex instructions and provide the complete out-of-band functionality of a service processor. The firmware implementing the IPMI interfaces is provided by various vendors.
A field replaceable unit
(FRU) holds the inventory, such as vendor ID and manufacturer, of potentially replaceable devices. A sensor data record (SDR) repository provides the properties of the individual sensors present on the board. For example, the board may contain sensors for temperature, fan speed, and voltage.
embedded on the motherboard
of a computer
, generally a server
. The BMC manages the interface between system management software and platform hardware.
Different types of sensor
s built into the computer system report to the BMC on parameter
s such as temperature
, cooling fan
speed
s, power
status, operating system
(OS) status, etc. The BMC monitors the sensors and can send alerts to a system administrator
via the network
if any of the parameters do not stay within preset limits, indicating a potential failure of the system. The administrator can also remotely communicate with the BMC to take some corrective action such as resetting or power cycling the system to get a hung OS running again. These abilities save on the total cost of ownership
of a system.
Physical interfaces to the BMC include SMBus busses, an RS-232
serial
console, address and data lines and an Intelligent Platform Management Bus (IPMB), that enables the BMC to accept IPMI request messages from other management controllers in the system.
A direct serial connection to the BMC is not encrypted
as the connection itself is secure. Connection to the BMC over LAN may or may not use encryption depending on the security concerns of the user.
computer system interface
Interface (computer science)
In the field of computer science, an interface is a tool and concept that refers to a point of interaction between components, and is applicable at the level of both hardware and software...
used by system administrator
System administrator
A system administrator, IT systems administrator, systems administrator, or sysadmin is a person employed to maintain and operate a computer system and/or network...
s to manage a computer system and monitor its operation.
The development of this interface specification was led by Intel Corporation and is supported by more than two hundred computer systems vendors. Dell
Dell
Dell, Inc. is an American multinational information technology corporation based in 1 Dell Way, Round Rock, Texas, United States, that develops, sells and supports computers and related products and services. Bearing the name of its founder, Michael Dell, the company is one of the largest...
, Hewlett-Packard
Hewlett-Packard
Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
, Intel, and NEC Corporation announced IPMI v1.0 on 1998-09-16, v1.5 on 2001-03-01, and v2.0 on 2004-02-14.
Functionality
An IPMI sub-system operates independently of the operating systemOperating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
and allows administrators to manage a system remotely in the absence of an operating system or of the system management
Systems management
Systems management refers to enterprise-wide administration of distributed systems including computer systems. Systems management is strongly influenced by network management initiatives in telecommunications....
software. The monitored system may be powered off, but must be connected to a power source and the monitoring medium, typically a local area network
Local area network
A local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...
connection. IPMI can also function after the operating system has started, and exposes management data and structures to the system management software. IPMI prescribes only the structure and format of the interfaces as a standard, while detailed implementations may vary.
An implementation of IPMI version 1.5 can communicate via a direct serial
Serial communications
In telecommunication and computer science, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels...
connection or via a side-band local area network
Local area network
A local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...
(LAN) connection to a remote client
Client (computing)
A client is an application or system that accesses a service made available by a server. The server is often on another computer system, in which case the client accesses the service by way of a network....
. The side-band LAN connection utilizes the board network interface controller (NIC). This solution is less expensive than a dedicated LAN connection but also has limited bandwidth. Systems compliant with IPMI version 2.0 can also communicate via serial over LAN
Serial over LAN
Serial Over LAN is a mechanism that enables the input and output of the serial port of a managed system to be redirected over IP.On some managed systems, notably blade server systems, the serial ports on the managed computers are not normally connected to a traditional serial port socket...
. System administrators can then use IPMI messaging to query platform status, to review hardware logs, or to issue other requests from a remote console through the same connections. The standard also defines an alerting mechanism for the system to send a simple network management protocol
Simple Network Management Protocol
Simple Network Management Protocol is an "Internet-standard protocol for managing devices on IP networks. Devices that typically support SNMP include routers, switches, servers, workstations, printers, modem racks, and more." It is used mostly in network management systems to monitor...
(SNMP) platform event trap (PET).
Side-band and out-of-band
IPMI implements what is often called a side-band management LAN connection. This connection utilizes a System Management BusSystem Management Bus
The System Management Bus is a single-ended simple two-wire bus for the purpose of lightweight communication...
(SMBUS) interface between the BMC (Baseboard Management Controller) and the board Network Interface Controller (NIC). This solution has the advantage of reduced costs but also provides limited bandwidth – sufficient for text console redirection but not for video redirection. For example, when a remote computer is down the system administrator can access it through IPMI and utilize a text console. This will be sufficient for a few vital functions, such as checking the event log, accessing the BIOS setup and perform power on, power off or power cycle. However, more advanced functions, such as remote re-installation of an operating system, may require an out-of-band management
Out-of-band management
In computing, out-of-band management involves the use of a dedicated management channel for device maintenance...
approach utilizing a dedicated LAN Connection.
IPMI components
An IPMI sub-system consists of a main controller, called the baseboard management controller (BMC) and other management controllers distributed among different system modules that are referred to as satellite controllers. The satellite controllers within the same chassis connect to the BMC via the system interface called Intelligent Platform Management Bus/Bridge (IPMB) — an enhanced implementation of I²CI²C
I²C is a multi-master serial single-ended computer bus invented by Philips that is used to attach low-speed peripherals to a motherboard, embedded system, cellphone, or other electronic device. Since the mid 1990s, several competitors I²C ("i-squared cee" or "i-two cee"; Inter-Integrated Circuit;...
(Inter-Integrated Circuit). The BMC connects to satellite controllers or another BMC in another chassis via the Intelligent Platform Management Controller (IPMC) bus or bridge. It may be managed with the Remote Management Control Protocol (RMCP), a specialized wire protocol defined by this specification.
Several vendors develop and market BMC chips. A BMC utilized for embedded applications may have limited memory and require optimized firmware code for implementation of the full IPMI functionality. Highly integrated BMCs can provide complex instructions and provide the complete out-of-band functionality of a service processor. The firmware implementing the IPMI interfaces is provided by various vendors.
A field replaceable unit
Field Replaceable Unit
This article is primarily about FRUs in computers.A field replaceable unit is a circuit board, part or assembly that can be quickly and easily removed from a personal computer or other piece of electronic equipment, and replaced by the user or a technician without having to send the entire product...
(FRU) holds the inventory, such as vendor ID and manufacturer, of potentially replaceable devices. A sensor data record (SDR) repository provides the properties of the individual sensors present on the board. For example, the board may contain sensors for temperature, fan speed, and voltage.
Baseboard management controller
The baseboard management controller is the intelligence in the IPMI architecture. It is a specialized microcontrollerMicrocontroller
A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...
embedded on the motherboard
Motherboard
In personal computers, a motherboard is the central printed circuit board in many modern computers and holds many of the crucial components of the system, providing connectors for other peripherals. The motherboard is sometimes alternatively known as the mainboard, system board, or, on Apple...
of a computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
, generally a server
Server (computing)
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
. The BMC manages the interface between system management software and platform hardware.
Different types of sensor
Sensor
A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument. For example, a mercury-in-glass thermometer converts the measured temperature into expansion and contraction of a liquid which can be read on a calibrated...
s built into the computer system report to the BMC on parameter
Parameter
Parameter from Ancient Greek παρά also “para” meaning “beside, subsidiary” and μέτρον also “metron” meaning “measure”, can be interpreted in mathematics, logic, linguistics, environmental science and other disciplines....
s such as temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
, cooling fan
Fan (implement)
A hand-held fan is an implement used to induce an airflow for the purpose of cooling or refreshing oneself. Any broad, flat surface waved back-and-forth will create a small airflow and therefore can be considered a rudimentary fan...
speed
Speed
In kinematics, the speed of an object is the magnitude of its velocity ; it is thus a scalar quantity. The average speed of an object in an interval of time is the distance traveled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as...
s, power
Power (physics)
In physics, power is the rate at which energy is transferred, used, or transformed. For example, the rate at which a light bulb transforms electrical energy into heat and light is measured in watts—the more wattage, the more power, or equivalently the more electrical energy is used per unit...
status, operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
(OS) status, etc. The BMC monitors the sensors and can send alerts to a system administrator
System administrator
A system administrator, IT systems administrator, systems administrator, or sysadmin is a person employed to maintain and operate a computer system and/or network...
via the network
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
if any of the parameters do not stay within preset limits, indicating a potential failure of the system. The administrator can also remotely communicate with the BMC to take some corrective action such as resetting or power cycling the system to get a hung OS running again. These abilities save on the total cost of ownership
Total cost of ownership
Total cost of ownership is a financial estimate whose purpose is to help consumers and enterprise managers determine direct and indirect costs of a product or system...
of a system.
Physical interfaces to the BMC include SMBus busses, an RS-232
RS-232
In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DTE and a DCE . It is commonly used in computer serial ports...
serial
Serial communications
In telecommunication and computer science, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels...
console, address and data lines and an Intelligent Platform Management Bus (IPMB), that enables the BMC to accept IPMI request messages from other management controllers in the system.
A direct serial connection to the BMC is not encrypted
Encryption
In cryptography, encryption is the process of transforming information using an algorithm to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information...
as the connection itself is secure. Connection to the BMC over LAN may or may not use encryption depending on the security concerns of the user.
See also
- Out-of-band managementOut-of-band managementIn computing, out-of-band management involves the use of a dedicated management channel for device maintenance...
- Lights out management (LOM)
- HP Integrated Lights-Out (HP's implementation of IPMI)
- Dell DRAC (Dell's implementation of IPMI)
- IBM Remote Supervisor Adapter (IBM's out-of-band management products, including IPMI implmentations)
- MegaRACMegaRACThe MegaRAC from American Megatrends is a successful product line of Service Processors providing complete out-of-band, or Lights-out remote management of computer systems. MegaRAC Service Processors come in various formats - PCI cards, embedded modules, software-only...
(AMI's out of band management product) - Intel Active Management TechnologyIntel Active Management TechnologyIntel Active Management Technology is hardware-based technology for remotely managing and securing PCs out-of-band.Currently, Intel AMT is available in desktop PCs with Intel Core 2 processor with Intel vPro technology and available in laptop PCs with Centrino or Centrino 2 platform with vPro...
(iAMT, an Intel out-of-band management product- an alternative to IPMI) - DMTF Systems Management Architecture for Server HardwareSystems Management Architecture for Server HardwareThe Systems Management Architecture for Server Hardware is a suite of specifications that deliver industry standard protocols to increase productivity of the management of a data center....
(SMASH- an alternative to IPMI) - DMTF Alert Standard FormatAlert Standard FormatAlert Standard Format is a DMTF standard for remote monitoring, management and control of computer systems in both OS-present and OS-absent environments...
(ASF) - Wired for ManagementWired for ManagementWired for Management was a primarily hardware-based system allowing a newly built computer without any software to be manipulated by a master computer that could access the hard disk of the new PC to paste the install program. It could also be used to update software and monitor system status...
(WfM)
External links
- IPMI Home Website
- GNU FreeIPMI
- http://openipmi.sourceforge.net
- ipmiutil IPMI Management Utilities
- IPMItool
- http://www.coreipm.com coreIPM Project - Firmware for IPMI baseboard management (open source)