User's Guide

Configuring HyperFabric
Configuring HyperFabric with ServiceGuard
Chapter 4
78
How HyperFabric Handles Adapter Failures
HyperFabric adapters are handled differently than other types of networking adapters
(such as Ethernet, FDDI, and Fibre Channel) in the ServiceGuard environment. In the
non-HyperFabric cases, two network links are in a node, and one will be active and one
will be idle or in standby. In the case of an active link failure, ServiceGuard is notified
and the network traffic is switched to the standby adapter (which then becomes active).
However, in the case of HyperFabric, if two adapters are in a node, both will be active. If
one active HyperFabric adapter fails, its network traffic is switched to the other active
HyperFabric adapter in the node. (Throughput might be slower because only one active
adapter is now handling the network traffic.) This rearrangement is handled by the
HyperFabric software, and ServiceGuard is not notified. However, note that if all of the
HyperFabric adapters fail, HyperFabric does notify ServiceGuard. In both cases, though,
the events are logged to /var/adm/clic_log and /var/adm/syslog.log.
Example 1:
This example, illustrated by Figure 4-3 below, presents an HA configuration using
ServiceGuard with HyperFabric. Both of the HyperFabric adapters are active on node A.
The HyperFabric Resource Monitor reports the active status of the HyperFabric resource
to the Event Monitoring Service (EMS), which lets ServiceGuard know that the
HyperFabric resource is available to Packages A and B.
Figure 4-3 Node with Two Active HyperFabric Adapters
Example 2:
This example, illustrated by Figure 4-4 below, shows the same node after the failure of
one of the HyperFabric adapters. The remaining adapter in node A is now handling all
HyperFabric network traffic for the node. Because the HyperFabric resource is still
HF
adapter 0
HF
adapter 1
node A
Active
172.16.10.11
Adapter IP address:
Active
172.16.20.21
Adapter IP address:
Adapter
Adapter
Package
A
Package
B
HyperFabric
Resource Active