Managing HP Serviceguard A.11.20.10 for Linux, December 2012

your cluster without having to bring it down, you need to plan the initial configuration carefully.
Use the following guidelines:
• Set the Maximum Configured Packages parameter (described later in this chapter under
“Cluster Configuration Planning ” (page 81)) high enough to accommodate the additional
packages you plan to add.
• Networks should be pre-configured into the cluster configuration if they will be needed for
packages you will add later while the cluster is running. See “LAN Information ” (page 77).
See Chapter 7: “Cluster and Package Maintenance” (page 193), for more information about
changing the cluster configuration dynamically, that is, while the cluster is running.
4.2 Using Serviceguard with VMware Virtual Machines
HP Serviceguard for Linux is certified for deployment on Linux Virtual machines created on VMware
ESX server. This section describes the various configurations for Serviceguard for Linux clusters
using physical machine and VMware virtual machines running on ESX server, so as to provide
high availability for applications.
NOTE: Serviceguard is certified on VMware ESX guests, not on ESX hosts, and provides high
availability for applications, not for the virtual machines themselves.
VMware has a high availability (HA) clustering product called VMware HA and it can provide
some degree of protection from failures. VMware HA uses a simple model that detects only physical
server failures. When it detects those failures, it restarts the Virtual Machines from the failed server
on other servers running VMware. Running Serviceguard for Linux in the virtual machines provides
a significant level of extra protection. Serviceguard fails over an application when a large number
of failures occur, including:
• Failure of the application
• Failure of networking required by the application
• Failure of storage
• An operating system “hang” or the failure of virtual machine itself
• Failure of the physical machine
In addition, it provides the following advantages:
• Minimize both planned and unplanned downtime of VM guests
• Serviceguard for Linux failover is faster than the VMware HA
• Serviceguard for Linux rolling upgrade feature allows for less planned downtime
Since Serviceguard is designed to run on nodes and manage applications encapsulated within
packages, you can integrate Serviceguard with VMware VM, where the VM can be configured
as a Serviceguard node. In this configuration, the virtual machine is a member of a Serviceguard
cluster, allowing failover of application packages between other physical or VM nodes in the
cluster (Serviceguard runs within the VM guest).
4.2.1 Cluster configuration options
A Serviceguard cluster that includes VM nodes can consist of:
• Virtual machines on the same host (cluster-in-a-box; not recommended)
• Virtual machines on separate hosts
• VM and physical nodes
• All of the above
76 Planning and Documenting an HA Cluster