NonStop NS-Series Planning Guide (H06.04+)

Integrity NonStop NS-Series System Description
HP Integrity NonStop NS-Series Planning Guide—529567-005
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ServerNet Fabric I/O
restores the system to triplex operation. If failure of an LSU takes down its associated
logical processor, the operating system activates the backup processes in other logical
processors. The system runs user applications as if no failure occurred.
As with a duplex processor, the errant processor is reset, and then it is synchronized
with the running processors. If the failure rate exceeds a predetermined threshold
value within a period of time, the failing processor is reset and held for repair action.
ServerNet Fabric I/O
ServerNet 3 is used with Integrity NonStop NS-series systems, which employs fiber-
optic links exclusively and is a collection of connected routers and links that form a
flexible internal or external network. This is a high-speed network within an Integrity
NonStop NS-series system that connects NonStop Blade Complexes to the ServerNet
adapters and system I/O such as disks and Ethernet LANs by way of the switch boards
in the p-switches and IOAM enclosures. ServerNet connections can also exist to
NonStop S-series I/O enclosures.
The ServerNet network architecture is full-duplex, packet-switched, and point-to-point
in a star configuration. It employs two independent I/O communications paths
throughout the system: the ServerNet X fabric and the ServerNet Y fabric. These dual
paths ensure that no single failure disrupts communications among the remaining
system components.
This section provides an overview of the ServerNet network in the Integrity NonStop
NS-series systems. For further information on the ServerNet network, protocols, IP
addresses, and naming conventions, see the Introduction to Networking for Integrity
NonStop NS-Series Servers.