Installation guide

Section 2.4:Steps for Setting Up and Connecting the Cluster Hardware 49
Figure 2–9 Dual-Controller RAID Array Connected to Single-Initiator Fibre
Channel Interconnects
If a dual-controller RAID array with two host ports on each controller is used, a Fibre Channel hub or
switch is required to connect each host bus adapter to one port on both controllers, as shown in Figure
2–9, Dual-Controller RAID Array Connected to Single-Initiator Fibre Channel Interconnects.
If a multi-initiator Fibre Channel is used, then a Fibre Channel hub or switch is required. In this case,
each HBA is connected to the hub or switch, and the hub or switch is connected to a host port on each
RAID controller.
Configuring Quorum Partitions
Two raw devices on shared disk storage must be created for the primary quorum partition and the
backup quorum partition. Each quorum partition must have a minimum size of 10 MB. The amount
of data in a quorum partition is constant; it does not increase or decrease over time.
The quorum partitions are used to hold cluster state information. Periodically, each cluster system
writes its status (either UP or DOWN), a timestamp, and the state of its services. In addition, the
quorum partitions contain a version of the cluster database. This ensures that each cluster system has
a common view of the cluster configuration.
To monitor cluster health, the cluster systems periodically read state information from the primary
quorum partition and determine if it is up to date. If the primary partition is corrupted, the cluster
systems read the information from the backup quorum partition and simultaneously repair the primary