An Ethernet connection directly from the SMN (Figure 2-1) to a local private or public LAN allows the system to be administered directly from a local or remote console via the SGI Management Center interface (most often installed on the SMN). Note that there is no direct inter-connected system controller function in the optional expansion PCIe modules.

The system controller network is designed into all IRUs. Controllers within the system report and share status information via the CMC Ethernet interconnect cables. This maintains controller configuration and topology information between all controllers in an SSI. Figure 2-2 shows an example system control network using an optional and separate (remote) workstation to monitor a single-rack SGI Altix UV 100 system. It is also possible to connect an optional PC or console directly to the SMN, see Figure 2-1.

For information on administering network connected SGI systems using the SGI Management Center, see the SGI Management Center System Administrator's Guide (P/N 007-5642-00x).

The CMC system for the SGI Altix UV 100 servers manages power control and sequencing, provides environmental control and monitoring, initiates system resets, stores identification and configuration information, and provides console/diagnostic and scan interface.

Viewing the system from the rear, the CMC blade is near the center of the IRU. The CMC accepts direction from the SMN and supports powering-up and powering-down individual or groups of compute blades and environmental monitoring of all units within the IRU. The CMC sends operational requests to the Baseboard Management Controller (BMC) on each compute/memory blade installed. The CMC provides data collected from the compute nodes within the IRU to the SMN upon request. Each CMC in a system communicates with other CMCs and the optional SMN via a private system control ethernet network.

CMCs can communicate with the blade BMCs and other IRU CMCs when they are linked together under a single system image (SSI); also called a partition. Each CMC shares its information with an optional SMN and other CMCs within the SSI. Note that the optional SMN (server), optional mass storage units and PCIe expansion enclosures do not have a CMC installed.

Each compute blade in an IRU has a baseboard management controller (BMC). The BMC is a built-in specialized microcontroller hardware component that monitors and reports on the functional “health” status of the blade. The BMC provides a key functional element in the overall Intelligent Platform Management Interface (IPMI) architecture.

The BMC acts as an interface to the higher levels of system control such as the IRU's CMC boards and the higher level control system used in the optional system management node. The BMC can report any on-board sensor information that it has regarding temperatures, power status, operating system condition and other functional parameters that may be reported by the blade.When any of the preset limits fall out of bounds, the information will be reported by the BMC and an administrator can take some corrective action. This could entail a node shutdown, reset (NMI) or power cycling of the individual blade.

The individual blade BMCs do not have information on the status of other blades within the IRU. This function is handled by the CMCs and/or the optional SMN. Note that blades equipped with an optional BaseIO riser board have a dedicated BMC Ethernet port.

The following list summarizes the control and monitoring functions that the CMC performs. Many of the controller functions are common across all IRUs, however, some functions are specific to the type of enclosure.

The SGI optional 1U console is a rackmountable unit that includes a built-in keyboard/touchpad, and uses a 17-inch (43-cm) LCD flat panel display of up to 1280 x 1024 pixels.