Wednesday, July 29, 2009

ASM Instance

Manually Creating an ASM Instance:
Automatic Storage Management (ASM) is a new feature in Oracle10g that alleviates the DBA from having to manually manage and tune disks used by Oracle databases. ASM provides the DBA with a file system and volume manager that makes use of an Oracle instance (referred to as an ASM instance) and can be managed using either SQL or Oracle Enterprise Manager.

Only one ASM instance is required per node. The same ASM instance can manage ASM storage for all 10g databases running on the node.

When the DBA installs the Oracle10g software and creates a new database, creating an ASM instance is a snap. The DBCA provides a simple check box and an easy wizard to create an ASM instance as well as an Oracle database that makes use of the new ASM instance for ASM storage. But, what happens when the DBA is migrating to Oracle10g or didn't opt to use ASM when a 10g database was first created. The DBA will need to know how to manually create an ASM instance and that is what this article provides.

  1. Overview
  2. Configuring Oracle Cluster Synchronization Services (CSS)
  3. Creating the ASM Instance
  4. Identify RAW Devices
  5. Starting the ASM Instance
  6. Verify RAW / Logical Disk Are Discovered
  7. Creating Disk Groups
  8. Using Disk Groups
  9. Startup Scripts

Go through the below link to cover all the above topic.

Note: Automatic Storage Management (ASM) requires the use of Oracle Cluster Synchronization Services (CSS), and as such, CSS must be configured and running before attempting to use ASM. The CSS service is required to enable synchronization between an ASM instance and the database instances that rely on it for database file storage.

With Oracle10g R1, CSS was always configured regardless of whether you chose to configure ASM or not. On the Linux / UNIX platform, CSS was installed and configured via the script. This caused a lot of problems since many did not know what this process was, and for most of them, didn't want the CSS process running since they were not using ASM.

Oracle listened carefully to the concerns (and strongly worded complaints) about the CSS process and in Oracle10g R2, will only configure this process when it is absolutely necessary. In Oracle10g R2, for example, if you don't choose to configure an ASM stand-alone instance or if you don't choose to configure a database that uses ASM storage, Oracle will not automatically configure CSS in the script.

In the case where the CSS process is not configured to run on the node (see above), you can make use of the $ORACLE_HOME/bin/localconfig script in Linux / UNIX or %ORACLE_HOME%\bin\localconfig.bat batch file in Windows. For example in Linux, run the following command as root to configure CSS outside of the script after the fact:

Friday, July 24, 2009

Oracle in the Cloud

Check out this SlideShare Presentation: Lovely presentation: Oracle in Cloud technology

Oracle Cloud Computing

Cloud computing center of Oracle:
Oracle has played a pioneering role in making Grid Computing relevant to enterprises with ground breaking products such as Oracle Real Applications Clusters (RAC), Automatic Storage Management (ASM), and Storage Grid.

More recently, Oracle has brought Grid Computing to middleware with the Application Grid approach to infrastructure. These products/technologies make the enterprise IT infrastructure elastic so that it can grow incrementally without any theoretical upper limit, as well as provide the flexibility to move resources around in order to meet dynamic business priorities.

In September 2008, Oracle introduced new offerings that allow enterprises to benefit from the developments taking place in the area of Cloud Computing. As a part of our initial offering, Oracle has partnered with Amazon Web Services (AWS) to offer the following products and services:

•Deploy Oracle Software in the Cloud
•Backup Oracle Database in the Cloud

These offerings may be extended to other Cloud platforms in the future. Check the below links for more details:

Deploying Oracle Database in the Cloud
Following is a demo/tutorial for deploying database in cloud.

Backing up Database in the Cloud
Following is a demo/tutorial for backing up database in the cloud.

Wednesday, July 22, 2009

RAC Filesystem Options

Storage Options for RAC:
In this section we are going to discuss various file system options available to host Oracle Real application Cluster. Lets first understand what are all those file system and then we will see which file systems support Oracle RAC.

Following are the storage options to store Oracle database for RAC.

Raw: Raw Devices
ASM: Automatic Storage Management
CFS: Cluster File System
OCFS: Oracle Cluster File System
LVM: Logical Volume Manager
NFS: Network File System

Now lets find out what are all the physical stuffs that makes a Oracle Database:

1: Oracle Software (Called as Oracle Binaries)
2: Oracle Dumps (Known as bdump, cdump, udump, adump and spfile/pfile etc)
3: Oracle database files (Data files, Control Files and Redo log files )
4: Recovery Files (Oracle Archives and Oracle Flash back)
5: CRS Files (OCR (Oracle Cluster Registry) and Voting Disk. Applicable only for RAC database.)

As you know the above files are required to set up a database (Single Instance/RAC). Lets see which storage option is compatible to host these files:

Supported: Oracle Database Files and CRS
Not Supported: Oracle Software, Recovery files and Oracle Dumps
Platform: All Platforms

Supported: Oracle Database Files and Recovery Files
Not Supported: Oracle Software, CRS and Oracle Dumps
Platform: All Platforms

Supported: All
Not Supported: None
Platform: AIX, HP Tru64 UNIX, SPARC Solaris

Supported: Oracle Database Files, CRS and Recovery Files
Not Supported: Oracle Software and Oracle Dumps
Platform: Windows, Linux

Supported: All
Not Supported: None
Platform: HP-UX, HP Tru64 UNIX, SPARC Solaris

Supported: All
Not Supported: None
Platform: Linux, SPARC Solaris

Thursday, July 16, 2009

Convert Single Instance Database to RAC and ASM

Convert a Single Instance Database to Oracle RAC 10g on RHEL3:

Learn how to convert a single-instance database to Oracle Real Application Clusters (RAC) 10g on Red Hat Enterprise Linux 3 (RHEL3), step by step.
Step 1: Preliminary Installation
Step 2: Migrate Your Database to ASM
Step 3: Install Cluster Ready Services (CRS) Software
Step 4: Install Oracle RAC Software
Step 5: Post Installation
Step 6: Test Transparent Application Failover (TAF)Conclusion

Download for this article:
Oracle Database 10g Enterprise Edition and Clusterware for Linux x86
Oracle ASMlib Drivers

For those with limited hands-on experience, implementing Oracle RAC 10g can be an intimidating prospect. But it doesn't have to be that way.

In this guide, I'll provide the precise procedures for converting a single-instance Oracle 10g database to Oracle RAC on RHEL3. We'll use Oracle Automatic Storage Management (ASM), an integrated file system and a volume management solution built into the Oracle database kernel, for RAC database storage because it simplifies database storage management tasks while offering storage reliability and performance.

To summarize on a very high level, there are several ways to convert your database to RAC. If the database is small, you can consider installing a new RAC database on ASM and export/import your data from your current database to the RAC database. For a larger database, the preferred method would be to use RMAN to migrate the database files over to ASM.

The method demonstrated here is a two-phase approach:

first, migrating the data to ASM, and
second, converting the single-instance database to RAC.

If you are new to ASM, I would recommend taking this migration path to get familiar with ASM before leaping into ASM and RAC at the same time. (For more information about Oracle ASM, visit the Oracle ASM Product Center or refer to the documentation.)

This guide requires a basic understanding of RAC architecture and some familiarity with managing and administering Oracle Database and Red Hat Enterprise Linux. Refer to the documentation for details.

The detailed stepwise guidance is available at the below URL:

The above URL holds a beautiful document to migrate a single instance database from Cluster file system to ASM and to RAC.