Cluster Nodes

In a cluster that runs on any version of the Solaris OS that was released before the Solaris 10 OS, a node is a physical machine that contributes to cluster membership and is not a quorum device. In a cluster that runs on the Solaris 10 OS, the concept of a node changes. In this environment, a node is a Solaris zone that is associated with a cluster. In this environment, a Solaris host, or simply host, is one of the following hardware or software configurations that runs the Solaris OS and its own processes:

• A “bare metal” physical machine that is not configured with a virtual machine or as a hardware domain

• A Sun Logical Domains (LDoms) guest domain

• A Sun Logical Domains (LDoms) I/O domain

• A hardware domain

Depending on your platform, Sun Cluster software supports the following configurations:

• SPARC: Sun Cluster software supports from one to sixteen Solaris hosts in a cluster. Different hardware configurations impose additional limits on the maximum number of hosts that you can configure in a cluster composed of SPARC based systems. See SPARC: Sun Cluster Topologies for the supported configurations.

• x86: Sun Cluster software supports from one to eight Solaris hosts in a cluster. Different hardware configurations impose additional limits on the maximum number of hosts that you can configure in a cluster composed of x86 based systems. See x86: Sun Cluster Topologies for the supported configurations.

Solaris hosts are generally attached to one or more multihost devices. Hosts that are not attached to multihost devices use the cluster file system to access the multihost devices. For example, one scalable services configuration enables hosts to service requests without being directly attached to multihost devices.

In addition, hosts in parallel database configurations share concurrent access to all the disks.

• See Multihost Devices for information about concurrent access to disks.

• See SPARC: Clustered Pair Topology and x86: Clustered Pair Topology for more information about parallel database configurations.

All nodes in the cluster are grouped under a common name (the cluster name), which is used for accessing and managing the cluster.

Public network adapters attach hosts to the public networks, providing client access to the cluster.

Cluster members communicate with the other hosts in the cluster through one or more physically independent networks. This set of physically independent networks is referred to as the cluster interconnect.

Every node in the cluster is aware when another node joins or leaves the cluster. Additionally, every node in the cluster is aware of the resources that are running locally as well as the resources that are running on the other cluster nodes.

Hosts in the same cluster should have similar processing, memory, and I/O capability to enable failover to occur without significant degradation in performance. Because of the possibility of failover, every host must have enough excess capacity to support the workload of all hosts for which they are a backup or secondary.

Each host boots its own individual root (/) file system.