188  IBM Power 770 and 780 (9117-MMD, 9179-MHD) Technical Overview and Introduction
adapter or an internal storage device, the service action is always performed from the 
operating system of the partition owning that resource.
Clients can subscribe through the subscription services to obtain the notifications about the 
latest updates available for service-related documentation. The latest version of the 
documentation is accessible through the Internet.
4.4  Manageability
Several functions and tools help manageability so you can efficiently and effectively manage 
your system.
4.4.1  Service user interfaces
The service interface allows support personnel or the client to communicate with the service 
support applications in a server using a console, interface, or terminal. Delivering a clear, 
concise view of available service applications, the service interface allows the support team to 
manage system resources and service information in an efficient and effective way.
Applications that are available through the service interface are carefully configured and 
placed to give service providers access to important service functions.
Various service interfaces are used, depending on the state of the system and its operating 
environment. The primary service interfaces are the following items:
 Light Path and Guiding Light
For more information, see “Light Path” on page 184 and “Guiding Light” on page 184.
 Service processor, Advanced System Management Interface (ASMI)
 Operator panel
 Operating system service menu
 Service Focal Point on the Hardware Management Console
 Service Focal Point Lite on Integrated Virtualization Manager
Service processor
The service processor is a controller that is running its own operating system. It is a 
component of the service interface card.
The service processor operating system has specific programs and device drivers for the 
service processor hardware. The host interface is a processor support interface that is 
connected to the POWER processor. The service processor is always working, regardless of 
the main system unit’s state. The system unit can be in the following states:
 Standby (power off)
 Operating, ready to start partitions
 Operating with running logical partitions
Functions
The service processor is used to monitor and manage the system hardware resources and 
devices. The service processor checks the system for errors, ensuring that the connection to 
the management console for manageability purposes and accepting Advanced System 
Management Interface (ASMI) Secure Sockets Layer (SSL) network connections. The service