With Oracle VM Server for SPARC virtualization technology, you can create multiple I/O domains (control domain and alternate I/O domain) to provide redundant storage and network services to a guest Logical Domain. A typical cluster-setup configured to use multiple I/O domains has two physical systems. On each physical system, the control domain and alternate I/O domain provide I/O services from back-end storage and network devices to a Logical Domain.

If there is a failure of storage or network services from one of the domains, the guest Logical Domain continues to function on the same physical system because it gets I/O services from the other I/O domain. However, when there is failure of services from both the I/O domains on a physical system, the Logical Domain on the physical system fails.

Configure VCS on multiple I/O domains to manage a Logical Domain. VCS fails over the Logical Domain from one system to a Logical Domain on another system when services from both the domains fail.