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

VMs as Nodes), HP-UX virtual machines are used as actual Serviceguard cluster nodes to provide
the same HA failover capabilities found in traditional Serviceguard cluster configurations.
Essentially, you can use Integrity VM to consolidate Serviceguard clusters on to virtual machines.
VMs as Serviceguard Node cluster configurations can span across the following:
• VMs on separate VM Hosts
• VMs on the same VM Host
• VMs and separate physical nodes or vPars
With virtual machines and separate physical nodes or vPars, Serviceguard provides high
availability in the event of a virtual machine or application failure. A failed application can
restarted either within the same virtual machine or failed over to the physical node. With virtual
machines on separate VM Hosts, Serviceguard also provides high availability in the event of a
virtual machine, physical machine, or application failure. A failed application can be restarted
either within the same virtual machine or failed over to another node (either physical or virtual).
Two or more virtual machines can form a Serviceguard cluster operating within a single physical
node. This configuration is similar to using vPars within a single physical system to form a
cluster-in-a-box. In this configuration, a failed application can be restarted either within the same
virtual machine or failed over to another virtual machine operating on the same physical node.
NOTE: HP recommends that you do not use a cluster-in-a-box configuration for mission-critical
applications, because there is no electrical isolation between the virtual machine nodes and the
physical node hosting the virtual machine, which creates a single-point-of-failure (SPOF). The
VM Host can also be considered an SPOF.
11.2.1 VMs on Separate VM Hosts
Figure 11-1 shows the configuration of an application package that can fail over to a guest running
on a different VM Host system.
Figure 11-1 Guest Application Failover to a Guest on a Different VM Host
Serviceguard Cluster
VM Host VM Host
Guest VM1
Guest VM2
Serviceguard
Package Failover
Physical Node 1 Physical Node 2
In this configuration, the Serviceguard nodes are guests running on either separate hard partitions
(nPars) or HP Integrity servers. Note that Integrity VM does not run on soft partitions (vPars).
11.2.2 VMs on the Same VM Host
Figure 11-2 shows the configuration of an application package that can fail over to another guest
on the same VM Host system.
188 Using HP Serviceguard with Integrity VM