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

For information on various failure and recovery scenarios, see the Veritas Volume

Manager Troubleshooting Guide.

Enhancing the performance of SF Oracle RAC clusters

The main components of clustering that impact the performance of an SF Oracle

RAC cluster are:

■ Kernel components, specifically LLT and GAB

■ VCS engine (had)

■ VCS agents

Each VCS agent process has two components—the agent framework and the agent

functions. The agent framework provides common functionality, such as

communication with the HAD, multithreading for multiple resources, scheduling

threads, and invoking functions. Agent functions implement functionality that

is particular to an agent. For various options provided by the clustering

components to monitor and enhance performance, see the chapter "VCS

performance considerations" in the Veritas Cluster Server Administrator's Guide.

Veritas Volume Manager can improve system performance by optimizing the

layout of data storage on the available hardware. For more information on tuning

Veritas Volume Manager for better performance, see the chapter "Performance

monitoring and tuning" in the Veritas Volume Manager Administrator's Guide.

Veritas Volume Replicator Advisor (VRAdvisor) is a planning tool that helps you

determine an optimum Veritas Volume Replicator (VVR) configuration. For

installing VRAdvisor and evaluating various parameters using the data collection

and data analysis process, see the Veritas Volume Replicator Advisor User’s Guide.

Mounting a snapshot file system for backups increases the load on the system as

it involves high resource consumption to perform copy-on-writes and to read data

blocks from the snapshot. In such situations, cluster snapshots can be used to do

off-host backups. Off-host backups reduce the load of a backup application from

the primary server. Overhead from remote snapshots is small when compared to

overall snapshot overhead. Therefore, running a backup application by mounting

a snapshot from a relatively less loaded node is beneficial to overall cluster

performance.

Creating snapshots for offhost processing

You can capture a point-in-time copy of actively changing data at a given instant.

You can then perform system backup, upgrade, and other maintenance tasks on

the point-in-time copies while providing continuous availability of your critical

Administering SF Oracle RAC and its components

Administering SF Oracle RAC