Automatic Storage Management

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Automatic Storage Management

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Enterprises are preferably switching from old existing Oracle versions, such as Oracle 8i and Oracle 9i, to Oracle 10g to have various additional profitable features. They often employ the Automatic Storage Management (ASM) option to enhance the manageability and consolidation of a database.

Oracle 10g

Oracle 10g is a revolutionary product in Oracle's grid computing world. Oracle 10g is a DBMS, which can automate many database tasks. Oracle 10g follows the Oracle's 9i platform; the letter 'g' in Oracle 10g signifies grid computing.

Oracle 10g delivers numerous interesting and dynamic new features. In this article, Automatic Storage Management (ASM) is explained in detail. There are many features available in Oracle 10g that help manage database operations more efficiently. One of the pivotal features of Oracle 10g is Automatic Storage Management (ASM). It is one of the storage options available in Oracle 10g.

Basic Functions of ASM

ASM relieves the burden of disk and storage management by defining the disk groups for file management, as a result of which file groups are reduced, and the time of the DBA is saved.

Note: The main function of ASM is to simplify and automate the database to manage Oracle database files. The RAC helps in automating the database management.

RAC

RAC stands for Real Application Cluster, which is a component provided by Oracle in its 9i version and which is now also available in the 10g version. RAC enables a database to be installed across multiple servers.


The image below depicts a window in which the configuration settings of Automatic Storage Management are detailed. A candidate has to enter the disk group name, the level of mirroring/redundancy, and the requisite data that the cursor therein prompts for. Click the Next button to proceed further.




This article will mainly focus on the following:

• ASM overview
• New features in ASM

ASM Overview

ASM is a very dynamic feature of Oracle 10g, which provides a grouped file system with no further investment on the software.

With ASM, there is no need of enhancing the storage resources for database management. ASM's intelligent mirroring technology enables triple data protection. It is known as triple data protection because while configuring Automatic Storage Management, a user is provided three levels of redundancy, which are as follows:

• High
• Normal
• External

New Features in ASM

Following are the main new features of ASM:

1. ASM can support multiple database versions.
2. ASM enhances the manageability of the database.

ASM helps the DBA save money by optimizing storage utilization.

Oracle's 10g version has enhanced the ASM functionality in the clustered environment, allowing one ASM instance per client to manage all database instances in the cluster, which has removed the requirement of maintaining more than one ASM instance to manage individual database instances.

For higher availability and manageability, ASM's instance should be installed in a separate ORACLE_HOME parameter, which is ASM_HOME.

ASM enhances I/O performance, as the database files are intelligently distributed across the current active devices. While adding more resources, database file distribution is re-balanced, keeping the database up and running.

ASM has mirroring capability to enhance manageability, which means that ASM can keep duplicate copies of data as a backup for recovery purposes.

Note: DBAs should note that ASM is not general-purpose, and will not replace the OS file system because ASM's file resources are not directly managed by the OS, but rather it is the ASM's file resources, which are managed by the file management system of the OS.

Preparing hard disk for configuration of ASM

If the DBA is configuring ASM for Windows NT OS, then the following points should be taken into consideration:

• Investigate for enough space on the system's hard disk.
• Using the disk partitioning utility (DISKPART.EXE) of Windows creates primary disk partitions, deciding the size of each partition.

Following example can give an idea about how to create partitions:

C:\>Select disk1
C:\Disk1 selected.
C:\Create partition primary size = 100
C:\Partition created.
C:\Create partition primary size = 100
C:\Partition created.
...................

The following image depicts the list of volumes created via the DISKPART.EXE utility in a Windows NT environment.



This article helps in understanding the fundamental functionality of Automatic Storage Management (ASM).

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