Managing Serviceguard 11th Edition, Version A.11.16, Second Printing June 2004

Building an HA Cluster Configuration
Preparing Your Systems
Chapter 5194
Serviceguard has also been tested with non-default values for these two
network parameters:
• ip6_nd_dad_solicit_count - This network parameter enables the
Duplicate Address Detection feature for IPv6 address. For more
information, see “IPv6 Relocatable Address and Duplicate Address
Detection Feature” on page 431 of this manual.
• 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.
Serviceguard supports the tcp_keepalive_interval being changed in
the following configurations:
— Supported with Serviceguard A.11.14 or later.
— Supported on nodes running HP-UX 11.11 only.
The following requirements must also 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.
For more information, see “Tunable Kernel Parameters” and “Transport
Administrator’s Guide posted at http://docs.hp.com. Click “Browse by
Release” then choose your operating system.
Preparing for Changes in Cluster Size
If you intend to add additional nodes to the cluster online, while it is
running, ensure that they are connected to the same heartbeat subnets
and to the same lock disks as the other cluster nodes. In selecting a
cluster lock configuration, be careful to anticipate any potential need for
additional cluster nodes. Remember that a cluster of more than four