A topology is the connection scheme that connects the cluster nodes in the cluster to the storage platforms that are used in an Oracle Solaris Cluster environment. Oracle Solaris Cluster software supports any topology that adheres to the following guidelines.
An Oracle Solaris Cluster environment that is composed of SPARC-based systems supports from one to sixteen cluster nodes in a cluster. Different hardware configurations impose additional limits on the maximum number of nodes that you can configure in a cluster composed of SPARC based systems.
A shared storage device can connect to as many nodes as the storage device supports.
Shared storage devices do not need to connect to all nodes of the cluster. However, these storage devices must connect to at least two nodes.
You can configure Oracle VM Server for SPARC Software guest domains and I/O domains as cluster nodes. In other words, you can create a clustered pair, pair+N, N+1, and N*N cluster that consists of any combination of physical machines, I/O domains, and guest domains. You can also create clusters that consist of only guest domains and I/O domains.
Oracle Solaris Cluster software does not require you to configure a cluster by using specific topologies. The following topologies are described to provide the vocabulary to discuss a cluster's connection scheme. These topologies are typical connection schemes.
Oracle VM Server for SPARC Software guest domains: cluster in a box
Oracle VM Server for SPARC Software guest domains: single cluster spans two different physical cluster hosts (boxes)
Oracle VM Server for SPARC Software guest domains: clusters span two different hosts (boxes)
Oracle VM Server for SPARC Software guest domains: each guest domain is hosted by redundant I/O domains
The following sections include sample diagrams of each topology.