Managing HP Serviceguard A.11.20.20 for Linux, May 2013

NOTE: This applies to all IPv6 addresses, whether HOSTNAME_ADDRESS_FAMILY is set to
IPV6 or ANY.
• Cross-subnet configurations are not supported in IPv6-only mode.
• Virtual machines are not supported.
You cannot have a virtual machine that is either a node or a package if
HOSTNAME_ADDRESS_FAMILY is set to ANY or IPV6.
4.7.3.2.2 Recommendations for IPv6-Only Mode
IMPORTANT: Check the latest Serviceguard for Linux release notes for the latest instructions and
recommendations.
• If you decide to migrate the cluster to IPv6-only mode, you should plan to do so while the
cluster is down.
4.7.3.3 What Is Mixed Mode?
If you configure mixed mode (HOSTNAME_ADDRESS_FAMILY set to ANY, or cmquerycl -a
any) then the addresses used by the cluster, including the heartbeat, and Quorum Server addresses
if any, can be IPv4 or IPv6 addresses. Serviceguard will first try to resolve a node's hostname to
an IPv4 address, then, if that fails, will try IPv6.
4.7.3.3.1 Rules and Restrictions for Mixed Mode
IMPORTANT: See the latest version of the Serviceguard release notes for the most current
information on these and other restrictions.
• Red Hat 5 and Red Hat 6 clusters are not supported.
NOTE: This also applies if HOSTNAME_ADDRESS_FAMILY is set to IPv6; Red Hat 5 supports
only IPv4-only clusters.
• The hostname resolution file on each node (for example, /etc/hosts) must contain entries
for all the IPv4 and IPv6 addresses used throughout the cluster, including all STATIONARY_IP
and HEARTBEAT_IP addresses as well any private addresses. There must be at least one
IPv4 address in this file (in the case of /etc/hosts, the IPv4 loopback address cannot be
removed). In addition, the file must contain the following entry:
::1 localhost ipv6-localhost ipv6-loopback
For more information and recommendations about hostname resolution, see “Configuring
Name Resolution” (page 137).
• You must use $SGCONF/cmclnodelist, not ~/.rhosts or /etc/hosts.equiv, to
provide root access to an unconfigured node.
See “Allowing Root Access to an Unconfigured Node” (page 136) for more information.
• Hostname aliases are not supported for IPv6 addresses, because of operating system limitations.
NOTE: This applies to all IPv6 addresses, whether HOSTNAME_ADDRESS_FAMILY is set to
IPV6 or ANY.
90 Planning and Documenting an HA Cluster