Intelligent Platform Management Interface - Functionality

Functionality

IPMI is a message-based, hardware-level interface specification: an IPMI subsystem operates independently of the operating system (OS) (i.e. out-of-band) to allow administrators to manage a system remotely in the absence of an operating system or of the system management software, and thus can be used before an OS has booted (allowing e.g. BIOS settings to be remotely monitored or changed), when the system is powered down, or after OS or system failure, which is the key characteristic of IPMI compared with in-band system management by e.g. remote login such as SSH. Being a standardized interface and protocol allows systems management software based on IPMI to manage multiple disparate servers.

System administrators can use IPMI messaging to monitor platform status (e.g. system temperatures, voltages, fans, power supplies and chassis intrusion); to query inventory information; to review hardware logs of out-of-range conditions; or to perform recovery procedures such as issuing requests from a remote console through the same connections e.g. system power-down and rebooting, or configuring watchdog timers. The standard also defines an alerting mechanism for the system to send a simple network management protocol (SNMP) platform event trap (PET).

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 out-of-band local area network (LAN) or 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, whereby serial console output can be remotely viewed over the LAN. Systems implementing IPMI 2.0 typically also include KVM over IP, remote virtual media and out-of-band embedded web server interface functionality, although these are strictly outside of the scope of the IPMI interface standard.

DCMI (Data Center Management Interface) is a similar standard based on IPMI but designed to be more suitable for Data Center management: it uses the interfaces defined in IPMI, but minimizes the number of optional interfaces and includes power capping control, among other differences.