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
Member
System
1
Network
Memory Channel
Shared SCSI Bus
PCI SCSI
Adapter
Member
System
2
PCI SCSI
Adapter
Cluster File
System
root (/)
/usr
/var
Member 1
root (/)
swap
Quorum
Tru64
UNIX
Disk
Member 1
root (/)
swap
ZK-1588U-AI
1.6 Growing 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 1.6.1).
• A cluster with more storage, but the single SCSI bus is a single point
of failure (Section 1.6.2).
• 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 1.6.3).
Introduction 1–7
