Managing HP Serviceguard A.11.20.10 for Linux, December 2012

f. Sets the AUTOSTART_CMCLD=1. In SUSE Linux Enterprise Server 11 environment, the
RUN_PARALLEL parameter in the /etc/sysconfig/boot file, is set to "NO".
g. The host names of the nodes and quorum if specified, their IP addresses are validated
and updated in the /etc/hosts file.
h. The /etc/lvm/lvm.conf and /etc/lvm/lvm_$(uname -n).conf files are updated
to enable VG Activation Protection.
i. Creates and deploys the firewall rules.
If firewall is disabled on the system, the rules are stored at /tmp/sg_firewall_rules.
An appropriate log message is displayed on how to run this file for the rules to be applied.
NOTE: The modified files are backed up in the same directory as the original files with
".original" extension and the output is logged to the /tmp/cmpreparecl.log file. This log
file is a cumulative log of the configuration done on the node. Each time you run
cmpreparecl, logs are appended with appropriate time stamp.
For more information, and other options, see manpages for cmpreparecl (1m).
4.7.2 Heartbeat Subnet and Cluster Re-formation Time
The speed of cluster re-formation depends on the number of heartbeat subnets.
If the cluster has only a single heartbeat network, and a network card on that network fails,
heartbeats will be lost while the failure is being detected and the IP address is being switched to
a standby interface. The cluster may treat these lost heartbeats as a failure and re-form without
one or more nodes. To prevent this, a minimum MEMBER_TIMEOUT value of 14 seconds is required
for clusters with a single heartbeat network.
If there is more than one heartbeat subnet, and there is a failure on one of them, heartbeats will
go through another, so you can configure a smaller MEMBER_TIMEOUT value.
NOTE: For heartbeat configuration requirements, see the discussion of the HEARTBEAT_IP
parameter later in this chapter. For more information about managing the speed of cluster
re-formation, see the discussion of the MEMBER_TIMEOUT parameter, and further discussion under
“What Happens when a Node Times Out” (page 72), and, for troubleshooting, “Cluster
Re-formations Caused by MEMBER_TIMEOUT Being Set too Low” (page 250).
4.7.3 About Hostname Address Families: IPv4-Only, IPv6-Only, and Mixed Mode
Serviceguard supports three possibilities for resolving the nodes' hostnames (and Quorum Server
hostnames, if any) to network address families:
• IPv4-only
• IPv6-only
• Mixed
IPv4-only means that Serviceguard will try to resolve the hostnames to IPv4 addresses only.
IMPORTANT: You can configure an IPv6 heartbeat, or stationary or relocatable IP address, in
any mode: IPv4-only, IPv6-only, or mixed. You can configure an IPv4 heartbeat, or stationary or
relocatable IP address, in IPv4-only or mixed mode.
IPv6-only means that Serviceguard will try to resolve the hostnames to IPv6 addresses only.
Mixed means that when resolving the hostnames, Serviceguard will try both IPv4 and IPv6 address
families.
You specify the address family the cluster will use in the cluster configuration file (by setting
HOSTNAME_ADDRESS_FAMILY to IPV4, IPV6, or ANY), or by means of the -a of cmquerycl
4.7 Cluster Configuration Planning 83