Compaq AA-RHGWB-TE manual Member System

Figure 1–1 shows a generic two-node cluster with the minimum number of disks.

•Tru64 UNIX disk

•Clusterwide root (/), /usr, and /var

•Member 1 boot disk

•Member 2 boot disk

A minimum configuration cluster may have reduced availability due to the lack of a quorum disk. As shown, with only two-member systems, both systems must be operational to achieve quorum and form a cluster. If only one system is operational, it will loop, waiting for the second system to boot before a cluster can be formed. If one system crashes, you lose the cluster.

Figure 1–1: Two-Node Cluster with Minimum Disk Configuration and No Quorum Disk

Network

Member

System

1

PCI SCSI

Adapter

Memory Channel

Tru64

UNIX

Disk

Member

System

2

PCI SCSI

Adapter

Shared SCSI Bus

Cluster File	Member 1	Member 2
System
root (/)	root (/)	root (/)
/usr	swap	swap
/var
		ZK-1587U-AI

Figure 1–2 shows the same generic two-node cluster as shown in Figure 1–1, but with the addition of a quorum disk. By adding a quorum disk, a cluster may be formed if both systems are operational, or if either of the systems and the quorum disk is operational. This cluster has a higher availability than the cluster shown in Figure 1–1. See the TruCluster Server Cluster

1–6Introduction