Category Archives: RAC

In an Oracle Real Application Cluster environment, 2 or more instances concurrently access a single database. The main aim of Oracle RAC architecture is to implement a clustered database to provide scalability, high availability and performance of queries at instance level.
The following article describe these concepts in more detail: Components of RAC architecture
In this category, I will show you how to:
– Rename a RAC Cluster
– Stop/Start all RAC databases at once
– Create an ACFS filesystem

Stop/Start all RAC databases at once

Introduction

Stopping all RAC databases running on an ORACLE_HOME at once and saving the state before shutting them down is really helpfull when you are doing patching on a server.

In my case I have databases running on some nodes and not the others, it’s getting complicated to keep track of which database is running where. With this method you will shutdown all databases at once and keep track of the databases running on that node before shutting them down.

Stopping all RAC databases of an ORACLE_HOME

This command will stop all databases running on the ORACLE_HOME specified and save the state before the shutdown in a state file.

Starting all RAC databases of an ORACLE_HOME

This command uses a state file to restart all databases previously running on a node.

 

Creating an ACFS filesystem

ACFS

About ACFS filesystem

ACFS mean  Automatic Storage Management Cluster File System. This filesystem volume resides inside the ASM database and can be used to store database files but also any type of files with or without direct relation to the database.

Oracle ACFS does not support Oracle Grid Infrastructure or Oracle Cluster Registry voting files.

The ACFS filesystem can be extended dynamically without any service interruption, you just need to add space to the diskgroup hosting the ACFS volume and then extend the filesystem. Continue reading Creating an ACFS filesystem