Managing Serviceguard Nineteenth Edition, Reprinted June 2011

NOTE: CVM/CFS can be installed on any system in an IPv6–only cluster using HP
Serviceguard A.11.20 April 2011 patches with Veritas Storage Foundation™ 5.1 SP1 and
later, even if they are not configured.
This also means that the Serviceguard component of bundles that include Serviceguard cannot
be configured in IPV6 mode prior to Veritas Storage Foundation™ 5.1 SP1.
• HPVM is not supported IPv6-only mode. You cannot configure a virtual machine either as a
node or a package in an IPv6-only cluster.
Recommendations for IPv6-Only Mode
IMPORTANT: Check the current Serviceguard 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.
What Is Mixed Mode?
If you configure mixed mode (HOSTNAME_ADDRESS_FAMILY set to 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.
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.
• 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 159).
• 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 157) 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.
• Cross-subnet configurations are not supported.
This also applies if HOSTNAME_ADDRESS_FAMILY is set to IPV6. See “Cross-Subnet
Configurations” (page 29) for more information.
• VxVM, VxFS, and CVM/CFS are supported on HP Serviceguard A.11.20 April 2011 patches
with Veritas Storage Foundation™ 5.1 SP1 and later.
104 Planning and Documenting an HA Cluster