Installation guide

40 Chapter 2:Hardware Installation and Operating System Configuration
4. Set up the shared disk storage according to the vendor instructions and connect the cluster systems
to the external storage enclosure.See Section 2.4.4, Configuring Shared Disk Storage for more
information about performing this task.
In addition, it is recommended to connect the storage enclosure to redundant UPS systems. See
Section 2.4.3, Configuring UPS Systems for more information about using optional UPS systems.
5. Turn on power to the hardware, and boot each cluster system. During the boot-up process, enter
the BIOS utility to modify the system setup, as follows:
• Ensure that the SCSI identification number used by the HBA is unique for the SCSI bus it is
attached to. See Section A.5, SCSI Identification Numbers for more information about per-
forming this task.
• Enable or disable the onboard termination for each host bus adapter, as required by the storage
configuration. See Section 2.4.4, Configuring Shared Disk Storage and Section A.3, SCSI Bus
Termination for more information about performing this task.
• Enable the cluster system to automatically boot when it is powered on.
6. Exit from the BIOS utility, and continue to boot each system. Examine the startup messages to
verify that the Linux kernel has been configured and can recognize the full set of shared disks. Use
the dmesg command to display console startup messages. See Section 2.3.4, Displaying Console
Startup Messages for more information about using this command.
7. Verify that the cluster systems can communicate over each point-to-point Ethernet heartbeat con-
nection by using the ping command to send packets over each network interface.
8. Set up the quorum disk partitions on the shared disk storage. See Configuring Quorum Partitions
in Section 2.4.4 for more information about performing this task.
2.4.1 Configuring Heartbeat Channels
The cluster uses heartbeat channels as a policy input during failover of the cluster systems. For exam-
ple, if a cluster system stops updating its timestamp on the quorum partitions, the other cluster system
will check the status of the heartbeat channels to determine if additional time should be alloted prior
to initiating a failover.
A cluster must include at least one heartbeat channel. It is possible to use an Ethernet connection for
both client access and a heartbeat channel. However, it is recommended to set up additional heartbeat
channels for high availability, using redundant Ethernet heartbeat channels, in addition to one or more
serial heartbeat channels.
For example, if using both an Ethernet and a serial heartbeat channel, and the cable for the Ethernet
channel is disconnected, the cluster systems can still check status through the serial heartbeat channel.