HP Integrity Virtual Machines 4.2: Installation, Configuration, and Administration

Serviceguard and all of its processes, packages, and applications are running as a cluster in the
guest, just as Serviceguard considers the virtual machine environment as an alternative platform
type. Even with its independent management focus, you should consider certain interaction
between the virtual machine and Serviceguard environment.
Changes to the VM Host and virtual machine and resources associated with the virtual machine
might impact the Serviceguard environment running in the virtual machine, which could impact
performance and availability. To minimize this impact, you should failover all applications and
packages and optionally halt the node running on the virtual machine prior to making changes
on the VM Host.
Unlike a Serviceguard cluster based solely on physical hardware, redundancy and availability
is divided between the VM Host and the Serviceguard cluster. You should carefully consider
this arrangement when planning hardware and software upgrades.
11.3 VMs as Serviceguard Packages
This section describes how to configure a VM Host as a Serviceguard Package. Figure 11-4 shows
the configuration of an application package that can fail over to another guest on the same VM
Host system.
Figure 11-4 Virtual Machine Failover to Another Cluster Member
PowerRun Attn. Fault Remote PowerRun Attn. Fault Remote
Serviceguard
Package
Failover
VM Host 1 VM Host 2
Virtual
Machine
Serviceguard
Cluster
11.3.1 Cluster Components
The resources on the VM Host system configured as VMs as Serviceguard Packages are shared
by Serviceguard, the VM Host, and all the running guests. Some resources must be made exclusive
to Serviceguard, such as the heartbeat network, and some must be shared with the VM Host,
such as the VM Host operating system boot disk. Guests running simultaneously share the
remaining memory and processing power.
To provide a high level of availability, a typical cluster uses redundant system components, for
example two or more SPUs and two or more independent disks. This redundancy eliminates
single points of failure. In general, the more redundancy, the greater your access to applications,
data, and supportive services in the event of a failure.
In addition to hardware redundancy, you must have the software support that enables and
controls the transfer of your applications to another SPU or network after a failure. Servceguard
provides this support as follows:
194 Using HP Serviceguard with Integrity VM