Compaq AA-RHGWC-TE manual Growing a Cluster from Minimum Storage to a Nspof Cluster

Administration manual for a discussion of how and when to use a quorum disk.

Figure 1–2: Generic Two-Node Cluster with Minimum Disk Configuration and 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 1	Quorum
System
root (/)	root (/)	root (/)
/usr
	swap	swap
/var

ZK-1588U-AI

1.5Growing a Cluster from Minimum Storage to a NSPOF Cluster

The following sections take a progression of clusters from a cluster with minimum storage to a no-single-point-of-failure (NSPOF) cluster; a cluster where one hardware failure will not interrupt the cluster operation:

•A cluster with minimum storage for highly available applications (Section 1.5.1).

•A cluster with more storage, but the single SCSI bus is a single point of failure (Section 1.5.2).

•Adding a second SCSI bus allows the use of LSM to mirror the /usr and /var file systems and data disks. However, as LSM cannot mirror the root (/), member system boot, swap, or quorum disks, so full redundancy is not achieved (Section 1.5.3).

1–6Introduction