HP Serviceguard Version A.11.18 Release Notes, September 2008

In addition, in a site-aware disaster-tolerant cluster, you can use the SITE_PREFERRED
policy to configure packages to fail over to a node on a preferred site (for example, to
prevent a package from failing over to a node at a remote site when a local node is
eligible); and you can use the -S option to cmviewcl to restrict output to information
about the local site. Site-aware disaster-tolerant clusters require additional software;
see the documents listed under “For More Information” (page 42), and thecmviewcl
(1m) and cmmakepkg (1m) manpages.
Configuration Tasks
Cluster and package configuration tasks are affected as follows:
• You must use the -w full option to cmquerycl to discover actual or potential
nodes and subnets across routers.
• For modular packages, you must configure two new parameters in the package
configuration file to allow packages to fail over across subnets:
— ip_subnet_node - to indicate which nodes the subnet is configured on
— monitored_subnet_access - to indicate whether the subnet is configured on all
nodes (FULL) or only some (PARTIAL)
(For legacy packages, see “Configuring Cross-Subnet Failover” in Chapter 7 of the
15th edition of Managing Serviceguard.)
• You should not use the wildcard (*) for node_name in the package configuration
file, as this could allow the package to fail over across subnets when a node on the
same subnet is eligible. Instead, list the nodes in order of preference.
Restrictions
The following restrictions apply:
• All nodes in the cluster must belong to the same network domain (that is, the
domain portion of the fully-qualified domain name must be the same).
• The nodes must be fully connected at the IP level.
• A minimum of two heartbeat paths must be configured for each cluster node.
• There must be less than 200 milliseconds of latency in the heartbeat network.
• Each heartbeat subnet on each node must be physically routed separately to the
heartbeat subnet on another node; that is, each heartbeat path must be physically
separate:
— The heartbeats must be statically routed; static route entries must be configured
on each node to route the heartbeats through different paths.
— Failure of a single router must not affect both heartbeats at the same time.
What’s in this Release 41