HP XC System Software Administration Guide Version 4.0

Table Of Contents
nat for Network Address Translation
nagios for the Nagios Master service
NOTE: The nagios_monitor service is not eligible.
kdump for kernel dumps
hptc_cluster_fs for the /hptc_cluster file system
For more information on services, see Chapter 4 (page 57).
2.3 Availability Sets
A set of nodes is designated as an availability set during the configuration of the HP XC System
Software. These nodes provide failover and failback functionality. One node in the availability
set is typically the primary provider for the service. When the availability tool senses that the
node has failed, the other node in the availability set assumes the function of that service for the
same availability tool.
NOTE: For the HP Serviceguard availability tool, each availability set becomes an HP
Serviceguard cluster.
A node must be exclusive to its availability set; that is, a node cannot be assigned to more than
one availability set for the same availability tool.
The following sections provide information on determining which nodes comprise an availability
set, reimaging nodes in an availability set, and reconfiguring an availability set.
2.3.1 Determining Which Nodes Are in the Availability Set
Use the shownode config hostgroups command to list the nodes in the availability sets.
# shownode config hostgroups
hostgroups:
headnode: n16
serviceguard:avail1: n15
n16
serviceguard:avail2: n13
n14
serviceguard:avail3: n11
n12
This example shows three availability sets: avail1, avail2, and avail3.
2.3.2 Reconfiguring an Availability Set
Run the transfer_from_avail command, then the cluster_config utility to modify your
availability sets.
This example illustrates the use of the cluster_config utility to select HP Serviceguard as
the availability tool and assigns nodes n7 and n8 to an availability set:
# transfer_from_avail
.
.
.
# cd /opt/hptc/config/sbin
/opt/hptc/config/sbin
# ./cluster_config
The HP XC System Software Installation Guide describes the cluster_config utlity in detail.
46 Improved Availability