Silicon Graphics SGI Altix 450, User Manual

Page: 103 / 198

System Controller Interaction
007-4857-002 81
The system controller is designed into all IRUs. An Ethernet connection directly from the IRU to
a local private or public Ethernet allows the system to be administered directly from a local or
remote console. Note that there is no interconnected system controller function in the optional
storage modules.
The L1 controllers within the system report and share status information via the NUMAlink
cables, thus maintaining controller configuration and topology information between all controllers
in the system.
Note: Mass storage option enclosures are not specifically monitored by the system controller
network. Most optional mass storage enclosures have their own internal microcontrollers for
monitoring and controlling all elements of the disk array. See the owner’s guide for your mass
storage option for more information on this topic.
System Controller Interaction
In all Altix 450 servers all the system controllers communicate with each other in the following
ways:
• All IRU enclosures within an Altix 450 system communicate with each other through their
NUMAlink connections using low voltage differential signaling (LVDS).
• When connecting to the L2 host Ethernet connection on the system control board of an IRU,
the system controller spawns an L2 application providing L2 functionality.
L1 Controller
All Altix 450 IRUs have L1 controllers. The following subsections describe the basic features of
the L1 controllers:
• “L1 Controller Functions” on page 82
• “L1 Front Panel Display” on page 82
Note: For additional information on L1 controller commands, see the SGI L1 and L2 Controller
Software User’s Guide (007-3938-xxx).