Managing HP Serviceguard for Linux, Tenth Edition, September 2012

• You must use $SGCONF/cmclnodelist, not ~/.rhosts or /etc/hosts.equiv,
to provide root access to an unconfigured node.
NOTE: This also applies if HOSTNAME_ADDRESS_FAMILY is set to ANY. See
“Allowing Root Access to an Unconfigured Node” (page 158) for more information.
• If you use a Quorum Server, you must make sure that the Quorum Server hostname
(and the alternate Quorum Server address specified by QS_ADDR, if any) resolve
to IPv6 addresses, and you must use Quorum Server version A.04.00 or later. See
the latest Quorum Server release notes for more information; you can find them at
docs.hp.com under High Availability —> Quorum Server.
NOTE: The Quorum Server itself can be an IPv6–only system; in that case it can
serve IPv6–only and mixed-mode clusters, but not IPv4–only clusters.
• If you use a Quorum Server, and the Quorum Server is on a different subnet from
cluster, you must use an IPv6-capable router.
• 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 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.
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.
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.
102 Planning and Documenting an HA Cluster