IBM AIX HACMP SG24-5131-00, Hardware User Manual

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Cluster Planning
39
until it assumes the shared IP address. Consequently,
Clinfo makes known the boot address for this adapter.
In an HACMP for AIX environment on the RS/6000 SP, the
SP Ethernet adapters can be configured as service
adapters but
should not be configured for IP address
takeover. For the SP switch network, service addresses
used for IP address takeover are ifconfig alias addresses
used on the css0 network.
Standby Adapter A standby adapter backs up a service adapter. If a service
adapter fails, the Cluster Manager swaps the standby
adapter’s address with the service adapter’s address.
Using a standby adapter eliminates a network adapter as
a single point of failure. A node can have no standby
adapter, or it can have from one to seven standby
adapters for each network to which it connects. Your
software configuration and hardware slot constraints
determine the actual number of standby adapters that a
node can support.
The standby adapter is configured on a different subnet
from any service adapters on the same system, and its
use should be reserved for HACMP only.
In an HACMP for AIX environment on the RS/6000 SP, for
an IP address takeover configuration using the SP switch,
standby adapters are not required.
Boot Adapter IP address takeover is an AIX facility that allows one node
to acquire the network address of another node in the
cluster. To enable IP address takeover, a boot adapter
label (address) must be assigned to the service adapter
on each cluster node. Nodes use the boot label after a
system reboot and before the HACMP for AIX software is
started.
In an HACMP for AIX environment on the RS/6000 SP,
boot addresses used in the IP address for the switch
network takeover are ifconfig alias addresses used on
that css0 network.
When the HACMP for AIX software is started on a node,
the node’s service adapter is reconfigured to use the