Veritas Storage Foundation 5.1 SP1 for Oracle RAC Administrator"s Guide (5900-1512, April 2011)

Typical SF Oracle RAC cluster configuration with server-based

I/O fencing

Figure 1-9 displays a configuration using a SF Oracle RAC cluster (with two nodes),

a single CP server, and two coordinator disks. The nodes within the SF Oracle RAC

cluster are connected to and communicate with each other using LLT links.

Figure 1-9

CP server, SF Oracle RAC cluster, and coordinator disks

Coordinator disk Coordinator disk

CP server

Client Cluster

Node 1

Node 2

Application Storage

LLT links

TCP/IP

Fiber channel

I/O fencing enhancements provided by CP server

CP server configurations enhance disk-based I/O fencing by providing the following

new capabilities:

■ CP server configurations are scalable, and a configuration with three CP servers

can provide I/O fencing for multiple SF Oracle RAC clusters. Since a single CP

server configuration can serve a large number of SF Oracle RAC clusters, the

cost of multiple SF Oracle RAC cluster deployments can be significantly

reduced.

■ Appropriately situated CP servers can eliminate any coordinator disk location

bias in the I/O fencing process. For example, this location bias may occur where

due to logistical restrictions two of the three coordinator disks are located at

a single site, and the cost of setting up a third coordinator disk location is

prohibitive.

Overview of Veritas Storage Foundation for Oracle RAC

About preventing data corruption with I/O fencing