Sun Java System Directory Server Enterprise Edition 6.2 Deployment Planning Guide

Hardware Redundancy

The architecture of a Sun Cluster hardware system is designed so that no SPOF can make a cluster unavailable. Redundant high-speed interconnects, storage system connections, and public networks ensure that cluster connectivity does not experience single failures.

Clients connect to the cluster through public network interfaces. If a network adapter card has multiple hardware interfaces, the card can connect to one or more public networks. You can set up nodes to include multiple network interface cards. The cards are configured so that one card is active, and the other cards operate as backups.

A cluster file system is a proxy between the kernel on one or more nodes and the underlying file system and volume manager. The cluster file system runs on a node that has a physical connection to the disks. For a cluster file system to be highly available, you must attach the disks to multiple nodes. A local file system that is made into a cluster file system is not highly available. A local file system implies a file system that is stored on a node's local disk.

A volume manager provides for mirrored or RAID 5 configurations for data redundancy of multihost disks. You can combine multihost disks with disk mirroring and striping to protect against both node failure and individual disk failure.

The cluster interconnect is a private network that transfers cluster-private communications and data service communications between cluster nodes. Redundant NICs, junctions, and cables protect against network failure.