What is a Service Processor?
A service processor is a separate, dedicated internal processor located on the motherboard of a server, a PCI card, or on the chassis of a blade server or telecommunications platform. It operates independently from the server’s CPU and operating system (OS), even if the CPU or OS is locked up or otherwise inaccessible.
Service processors monitor a server’s on-board instrumentation (temperature sensors, CPU status, fan speed, voltages), provide remote reset or power-cycle capabilities, enable remote access to basic input/output system (BIOS) configuration or OS console information, and, in some cases, provide keyboard and mouse control.
Depending on the manufacturer, service processors may also provide console redirection capabilities to view server processes or to configure server parameters, system information on components installed, including ports used and devices connected, and event logs, notifications and alarms.
Some leading service processor technologies include:
- Intelligent Platform Management Interface (IPMI)
- HP Integrated Lights Out (iLO)
- IBM® Remote Supervisor Adapter (RSA)
- Dell Remote Assistant Card (DRAC)
- Sun Advanced Lights Out Management (ALOM)
- Sun Integrated Lights Out Management (ILOM)
Service processors are accessible through either a dedicated Ethernet interface (out-of-band) or a shared data Ethernet interface (sideband). See below.
Note that with sideband access, although there is only one Ethernet jack in use at the back of the server, there are still two Ethernet hardware sets inside the server, which means those interfaces can have separate IP addresses.