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The system must meet the
following hardware and software requirements to convert to RAC:
* Be able to run a cluster file
* Have the required additional
license(s) for Oracle Database 10g Enterprise Edition with RAC.
* Have at least two network
interface cards of at least 100 mbit/sec, the preference is a
Gigabyte or better, communication speed. One for the public and
virtual private interface and the other for the RAC cluster
* Have shared disk storage
The conversion from a single
instance to clustered configuration will be covered first.
Conversion from Single
Instance to Cluster-Enabled System Administrative Concerns
Before beginning the conversion
to RAC, the following administrative considerations should be
* Make sure there are adequate
backup procedures before converting from a single instance Oracle
database to RAC. This may involve the use of RMAN, transportable
tablespaces or the RMAN CONVERT utility.
* The additional archiving
considerations that apply in RAC environments must be considered.
For example, the archive file format requires a thread number.
This is done automatically for DBCA created RAC instances. In
addition, the archived logs from all instances of a RAC database are
required for media recovery. This means that if information is
archived to a file and a cluster file system is not in used, a
method of accessing the archive logs from all nodes on which the
cluster database has instances, such as NFS, is required where file
systems are not shared.
All right, the following section
provides more information on the actual conversion procedure from
single instance to RAC on Oracle Database 10g.
Converting from Single
Instance to 10g RAC
It is strongly recommended that
the Database Configuration Assistant (DBCA) be used to convert from
single instance Oracle to 10g RAC. Oracle has added many new
features such as CRS, Virtual IP management, and GRID control which
can make the conversion difficult. Use of the DBCA utility provides
the following benefits:
* Automation of the
configuration of the control file attributes
* Creation of the needed undo
tablespaces and the redo logs
* Makes the initialization
parameter file entries for cluster-enabled environments.
* Configuration of the Oracle
* Configuration of the Cluster
Ready Services (CRS) resources
* Configuration of the EM (Grid
control) and SRVCTL to allow for RAC database management
This section will describe the
* Conversion of a single
instance on a Non-Clustered system to Oracle Database 10g with RAC
* Conversion of a single
instance on a Cluster to Oracle Database 10g RAC
Single Instance on a
Non-Clustered System to Oracle Database 10g with RAC
Conversion from a single
instance, non-clustered database to a clustered RAC system involves
the following procedures, performed in the order given:
* Backup the original single
* Perform the required
* Set up the cluster environment
* Copy the preconfigured
database image into the cluster
* Install the Oracle Database
10g RAC software
The following sections will
detail each of these procedures.
Duplication of the Original
Single Instance Database
The Database Configuration
Assistant (DBCA) should be used to create a preconfigured image of
the single instance database. This is accomplished by invoking the
DBCA from the bin directory under oracle_home and following the menu
path as follows: Welcome Manage Templates --> Create a
database template [select From an existing database (structure as
well as data)] --> Database Name [select the database name] -->
Template Name [enter template name, use database name as the
default, and description and template datafile location] --> Finish.
The DBCA will then generate two
* The database structure file (template_name.dbc)
* The database preconfigured
image file (template_name.dfb)
By default, these files are
generated on UNIX in the oracle_home/assistants/dbca/templates
directory and in the %oracle_home%\assistants\dbca\templates
directory on Windows -based systems.