Supplementary Hardware Information; Attached Storage Requirements; Setting Up A Fibre Channel Interconnect - Red Hat CLUSTER SUITE - CONFIGURING AND MANAGING A CLUSTER 2006 Manual

Appendix A.

Supplementary Hardware Information

The following sections provide additional information about configuring the hardware used
in a cluster system.
A.1. Attached Storage Requirements
The following sections detail the steps to consider when directly connecting storage de-
vices to cluster nodes, whether using SCSI host-bus adapters or Fibre Channel connections.
A.2. Setting Up a Fibre Channel Interconnect
Fibre Channel can be used in either single-initiator or multi-initiator configurations.
A single-initiator Fibre Channel interconnect has only one node connected to it. This may
provide better host isolation and better performance than a multi-initiator bus. Single-
initiator interconnects ensure that each node is protected from disruptions due to the work-
load, initialization, or repair of the other node.
If employing a RAID array that has multiple host ports, and the RAID array provides
simultaneous access to all the shared logical units from the host ports on the storage enclo-
sure, set up single-initiator Fibre Channel interconnects to connect each node to the RAID
array. If a logical unit can fail over from one controller to the other, the process must be
transparent to the operating system.
Figure A-1 shows a single-controller RAID array with two host ports and the host bus
adapters connected directly to the RAID controller, without using Fibre Channel hubs or
switches. When using this type of single-initiator Fibre Channel connection, your RAID
controller must have a separate host port for each cluster node.