Managing HP Serviceguard for Linux, Tenth Edition, September 2012

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.
• 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” (page 279).)
• 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; failing over across subnets can take longer than failing over
on the same subnet. List the nodes in order of preference instead of using the
wildcard.
• You should configure IP monitoring for each subnet; see “Monitoring LAN Interfaces
and Detecting Failure: IP Level” (page 75).
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.
• IPv6 heartbeat subnets are not supported in a cross-subnet configuration.
• IPv6–only and mixed modes are not supported in a cross-subnet configuration. For
more information about these modes, see “About Hostname Address Families:
IPv4-Only, IPv6-Only, and Mixed Mode” (page 100).
28 Understanding Hardware Configurations for Serviceguard for Linux