Glossary

Baseboard Management Controller. The IPMI spec describes the BMC as the "heart of IPMI". It is an embedded microcontroller surrounded by memory, interfaces, and sensors. The entire collection can provide the various functions described in the specification.

Block Transfer. One of the System Interfaces used to connect a BMC to a system CPU. BT is used in HP Integrity midrange and highend systems. It transfers data in blocks and is much faster than KCS or SMIC.

Forward Progress Log. An HP Integrity extension to IPMI, modelled on the SEL. It is a more verbose log of system activity that covers informational items, as well as everything that goes into the SEL. It is a circular log and never needs to be cleared.

Field Replaceable Unit. Recognized as an industry-standard acronym, FRU is also tightly defined under IPMI specifications for data exchange. It describes any item or assembly that can be replaced outside of the factory. It may or may not require an HP-certified technician to do the replacement

Integrated Lights Out. The product name for the management processor found on HP ProLiant servers. Recent firmware upgrades Integrity server legacy MP cards to Integrity iLO cards; it is this firmware that supplies RMCP.

Intelligent Platform Managment Bus. An I2C serial link between two intelligent IPMI controllers such as a BMC and an MP card. While this does exist in some Integrity servers, the implementation is hidden by hpbmc.

Intelligent Platform Management Initiative. A specification owned by Intel to describe mechanisms and devices to completely offload the task of managing system hardware from the primary CPU. This includes inventory management, entity relationships, sensor values, scanning and event management, inter-device and inter-chassis communication, and more. See http://www.intel.com/design/servers/ipmi/.

Keyboard Controller Style. One of the System Interfaces used to connect a BMC to a system CPU. It is based on the protocol of the legacy Intel 805x keyboard controller chips (hence the name). It has a low-pin count which makes it simple and inexpensive, but its per-byte handshaking scheme makes it slow. KCS is used with the BMCs on HP Integrity entry-level servers.

Management Processor. Generic term for processing, storage, sensor, and offline/remote access resources. This usually exists as separate cards or coprocessors. Early entry-level systems ship with an optional MP card, and all midrange and highend systems always have an MP card. Current firmware upgrades the functionality to Integrity iLO cards as they now are on par with HP ProLiant servers.

Open IPMI refers to an open-source project whose details can be seen at http://openipmi.sourceforge.net/. It was started independently of the Linux kernel effort to bring IPMI to Linux. Since 2.4.23 and 2.6, the Open IPMI driver has been fully integrated into the linux kernel at http://kernel.org/.

The Open IPMI driver consists of three modules that present a stack. The middle layer, ipmi_msghandler, keeps track of multiple messages from multiple users and devices. The upper layer, ipmi_devintf, presents a character device file for user programs to use via ioctl. The bottom layer, ipmi_si, presents plugs the message handler into the three system interfaces (BT, KCS, or SMIC) of the system BMC.

Historically the Open IPMI modules have been slightly out of sync with HP Integrity server BMC hardware. hpmgmtbase was initially released to provide compatible drivers, and now includes other utilities.

Open IPMI is not needed for RMCP operations.

The Open IMPI project also delivers a user library which is not used by any HP products. HP supplies its own proprietary library as part of hpmgmtbase.

Remote Management Control Protocol. A network IP-based protocol that provides authentication, access, and session management for management utilities. It can carry embedded IPMI commands and responses between network entities.

Sensor Data Record Repository. A required feature of a BMC, this is the material list for IPMI. It starts with the list of sensors, their conversion and units, thresholds, and scanning information. The SDRR also holds FRU lists, entity associations, and HP proprietary entries. The SDRR completely describes the resources of an HP Integrity Server.

System Event Log. A required feature of a BMC, this non-volatile log holds detected events that are important or critical to system operation and may be very useful in post-mortem crash analysis. It is an append-log, and when full will accept no new events. The hpseld program monitors the capacity, maintains a disk copy, and clears the log when necessary.

Server Management Interface Chip. One of the System Interfaces used to connect a BMC to a system CPU. This is a generic design best utilized when the BMC appears as a PCI device. SMIC is not used on HP Integrity Servers.

Simple Network Management Protocol. Methods, data structures, and protocols defined in RFC1155, 1156, and 1157 (earliest references) for data access and control of systems over a network. SNMP development began in the early 1980s; today it is both a ubiquitous standard, but also suffers from design hindsight in security and data complexity.

hpmgmtbase does not directly perform any SNMP operations but its libraries are used by products that do, such as the Systems Insight Manager SNMP Agents for HP Integrity Servers.

Web-Based Enterprise Management. (pronounced (web-em). Methods, data structures, and protocols defined by the DMTF (http://www.dmtf.org) for data access and control of systems over a network. WBEM development began in the late 1990s, and is rich in object-oriented techniques and secure access. Its acceptance is gaining at the time of writing (2006). While it will probably never replace SNMP, it will supplant it in newer systems and designs.

hpmgmtbase does not directly perform any WBEM operations but its libraries are used by products that do, such Systems Insight Manager WBEM Providers for HP Integrity Servers.