HP Serviceguard A.11.20- Managing Serviceguard Twentieth Edition, August 2011

Advantages of Easy Deployment
• Quick and simple way to create and start a cluster.
• Automates security and networking configuration that must always be done before you configure
nodes into a cluster.
• Simplifies cluster lock configuration.
• Simplifies creation of shared storage for packages.
Limitations of Easy Deployment
• Does not install or verify Serviceguard software
• Requires agile addressing for disks. See “About Device File Names (Device Special Files)”
(page 80).
• cmpreparestg (1m) will fail if cDSFs and persistent DSFs are mixed in a volume group.
See “About Cluster-wide Device Special Files (cDSFs)” (page 104) for more information about
cDSFs.
• Does not configure access control policies.
• Does not install or configure firewall and related software.
• Does not support cross-subnet configurations.
• Does not configure packages.
• Does not discover or configure a quorum server (but can deploy one that is already configured).
• Does not support asymmetric network configurations (in which only a subset of nodes has
access to a given subnet).
For more information and instructions, see “Using Easy Deployment” (page 161).
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 88) ,“Modifying the MEMBER_TIMEOUT
Parameter” (page 192), and, for troubleshooting, “Cluster Re-formations Caused by
MEMBER_TIMEOUT Being Set too Low” (page 333).
About Hostname Address Families: IPv4-Only, IPv6-Only, and Mixed Mode
As of A.11.19, Serviceguard supports three possibilities for resolving the nodes' hostnames (and
Quorum Server hostnames, if any) to network address families:
• IPv4-only
• IPv6-only
• Mixed
106 Planning and Documenting an HA Cluster