Managing Serviceguard Eighteenth Edition, September 2010

Tuning Network and Kernel Parameters
Serviceguard and its extension products, such as SGeSAP and SGeRAC, have been
tested with default values of the network and kernel parameters supported by the ndd
and kmtune utilities.
You may need to adjust these parameters for larger cluster configurations and
applications.
• ndd is the network tuning utility. For more information, see the man page for ndd
(1m)
• kmtune is the system tuning utility. For more information, see the man page for
kmtune (1m).
Make adjustments with care, and if you experience problems, return the parameters
to their default values.
NOTE: If you contact HP support regarding Serviceguard or networking, please be
sure to mention any parameters that have been changed from their defaults.
Serviceguard has also been tested with non-default values for these network parameters:
• ip6_nd_dad_solicit_count — This network parameter enables the Duplicate Address
Detection feature for IPv6 addresses. You can find more information l under “IPv6
Relocatable Address and Duplicate Address Detection Feature” (page 480).
• tcp_keepalive_interval — This network parameter controls the length of time the
node will allow an unused network socket to exist before reclaiming its resources
so they can be reused.
The following requirements must be met:
— The maximum value for tcp_keepalive_interval is 7200000 (2 hours, the HP-UX
default value).
— The minimum value for tcp_keepalive_interval is 60000 (60 seconds).
— The tcp_keepalive_interval value must be set on a node before Serviceguard is
started on that node. This can be done by configuring the new
tcp_keepalive_interval in the /etc/rc.config.d/nddconf file, which will
automatically set any ndd parameters at system boot time.
— The tcp_keepalive_interval value must be the same for all nodes in the cluster.
• ip_strong_es_model — This network parameter controls support for the strong
end-system model, which prevents a system from acting as a router. For more
Preparing Your Systems 223