Oracle Database Online Documentation 1. Release 2 1. 0. 2Welcome to the Oracle Database 1. Documentation Library. Here you can research new information, look up reference information. Using Automatic Storage Management. This chapter discusses some of the concepts behind Automatic Storage Management and describes how to use it. It contains the following topics What Is Automatic Storage Management Automatic Storage Management ASM is an integrated file system and volume manager expressly built for Oracle database files. ASM provides the performance of raw IO with the easy management of a file system. It simplifies database administration by eliminating the need for you to directly manage potentially thousands of Oracle database files. It does this by enabling you to divide all available storage into disk groups. You manage a small set of disk groups and ASM automates the placement of the database files within those disk groups. In the SQL statements that you use for creating database structures such as tablespaces, control files, and redo and archive log files, you specify file location in terms of disk groups. ASM then creates and manages the associated underlying files for you. Mirroring and Striping. ASM extends the power of Oracle managed files. With Oracle managed files, files are created and managed automatically for you, but with ASM you get the additional benefits of features such as mirroring and striping. ASM divides files into 1 MB extents and spreads each files extents evenly across all disks in the disk group. This optimizes performance and disk utilization, making manual IO performance tuning unnecessary. ASM mirroring is more flexible than operating system mirrored disks because ASM mirroring enables the redundancy level to be specified on a per file basis. B25329_01/doc/install.102/b25143/img/install_folder.gif' alt='Oracle 10G Enterprise Edition For Windows 8 64 Bit' title='Oracle 10G Enterprise Edition For Windows 8 64 Bit' />Thus two files can share the same disk group with one file being mirrored while the other is not. Mirroring takes place at the extent level. If a file is mirrored, depending upon redundancy level set for the file, each extent has one or more mirrored copies, and mirrored copies are always kept on different disks in the disk group. Table 1. 2 1 describes the three mirroring options that ASM supports on a per file basis. Table 1. 2 1 ASM Mirroring Options. Mirroring Option. Description. 2 way mirroring. In todays post I will discuss on steps you should doneed for Oracle Apps R12 installation. Most of these steps are written w. Installation on Linux but I. There seems to be some forum threads with installing ODI in windows 7 Edition. I would like to throw some light and tweaks to make it work. ODI doesnt support. Installing Enterprise Manager System. This chapter describes how you can install a complete Enterprise Manager system using an existing, certified Oracle Database. Oracle Database est un systme de gestion de base de donnes relationnelle SGBDR qui depuis lintroduction du support du modle objet dans sa version 8 peut. Responses to Step by Step Oracle guides tejas patel Says December 8th, 2009 at 1231 pm. DBA. so please help me. What Is Automatic Storage Management Automatic Storage Management ASM is an integrated file system and volume manager expressly built for Oracle database files. Oracle Database 11g Release 2 Express Edition for Windows 64 now available for download. Oracle Database 11g Release 2 Express Edition downloads for Linux x86 and Windows. Each extent has 1 mirrored copy. Each extent has 2 mirrored copies. Unprotected. ASM provides no mirroring. Used when mirroring is provided by the disk subsystem itself. Dynamic Storage Configuration. ASM enables you to change the storage configuration without having to take the database offline. It automatically rebalancesredistributes file data evenly across all the disks of the disk groupafter you add disks to or drop disks from a disk group. Should a disk failure occur, ASM automatically rebalances to restore full redundancy for files that had extents on the failed disk. When you replace the failed disk with a new disk, ASM rebalances the disk group to spread data evenly across all disks, including the replacement disk. Interoperability with Existing Databases. ASM does not eliminate any existing database functionality. Existing databases using file systems or with storage on raw devices can operate as they always have. New files can be created as ASM files while existing ones are administered as before. Databases can have a mixture of ASM files and non ASM files. ASM Instance. ASM is implemented as a special kind of Oracle instance, with its own System Global Area SGA and background processes. The ASM instance typically has a much smaller SGA than a database instance. Single Instance and Clustered Environments. Each database server that has database files managed by ASM needs to be running an ASM instance. A single ASM instance can service one or more single instance databases on a stand alone server. Each ASM disk group can be shared among all the databases on the server. In a clustered environment, each node runs an ASM instance, and the ASM instances communicate with each other on a peer to peer basis. This is true for both Real Application Clusters RAC environments, and non RAC clustered environments where multiple single instance databases across multiple nodes share a clustered pool of storage that is managed by ASM. If a node is part of a Real Application Clusters RAC system, the peer to peer communications service is already installed on that server. If the node is part of a cluster where RAC is not installed, the Oracle Clusterware, Cluster Ready Services CRS, must be installed on that node. An ASM instance on a node in a cluster can manage storage simultaneously for one or more RAC database instances and one or more single instance databases. Overview of the Components of Automatic Storage Management. The components of Automatic Storage Management ASM are disk groups, disks, failure groups, files, and templates. Disk Groups. The primary component of ASM is the disk group. A disk group consists of a grouping of disks that are managed together as a unit. You configure ASM by creating disk groups to store database files. Oracle provides SQL statements that create and manage disk groups, their contents, and their metadata. Anti Spam Softwares Review. The disk group type determines the levels of mirroring that files in the disk group can be created with. You specify disk group type when you create the disk group. Table 1. 2 2 lists ASM disk group types, their supported mirroring levels, and their default mirroring levels. The default mirroring level indicates the mirroring level that a file is created with unless you designate a different mirroring level. See Templates, later in this section. Table 1. Mirroring Options for Each Disk Group Type. Disk Group Type. Supported Mirroring Levels. Default Mirroring Level. Normal redundancy. Unprotected none2 way. High redundancy. 3 way. External redundancy. Unprotected noneUnprotected. If you do not specify a disk group type redundancy level when you create a disk group, the disk group defaults to normal redundancy. As Table 1. 2 2 indicates, files in a high redundancy disk group are always 3 way mirrored, files in an external redundancy disk group have no ASM mirroring, and files in a normal redundancy disk group can be 2 way or 3 way mirrored or unprotected, with 2 way mirroring as the default. Mirroring level for each file is set by templates, which are described later in this section. Disks. The disks in a disk group are referred to as ASM disks. On Windows operating systems, an ASM disk is always a partition. On all other platforms, an ASM disk can be A partition of a logical unit number LUNA network attached file. Note. Although you can also present a volume a logical collection of disks for management by ASM, it is not recommended to run ASM on top of another host based volume manager. When an ASM instance starts, it automatically discovers all available ASM disks. Discovery is the process of determining every disk device to which the ASM instance has been given IO permissions by some operating system mechanism, and of examining the contents of the first block of such disks to see if they are recognized as belonging to a disk group. ASM discovers disks in the paths that are listed in an initialization parameter, or if the parameter is NULL, in an operating systemdependent default path. Failure Groups. Failure groups define ASM disks that share a common potential failure mechanism. An example of a failure group is a set of SCSI disks sharing the same SCSI controller. Failure groups are used to determine which ASM disks to use for storing redundant copies of data.