【标准】Oracle Optimal Flexible Architecture(OFA)简介

关于OFA（Optimal Flexible Architecture）标准的介绍

本文来源于Oracle官网，地址如下：

http://docs.oracle.com/cd/E11882_01/install.112/e24321/appendix_ofa.htm#i633068

1.Overview of the Optimal Flexible Architecture Standard

The Optimal Flexible Architecture standard helps you to organize database software and configure databases to allow multiple databases, of different versions, owned by different users to coexist.  Optimal Flexible Architecture assists in identification of ORACLE_BASE with its Automatic Diagnostic Repository (ADR) diagnostic data to properly collect incidents.

OFA 标准架构帮助我们组织Oracle 软件，配置数据库。通过OFA架构，我们可以安装多个数据库，这些数据库可以使用不同的版本，不同的用户。Oracle的OFA架构可以帮助数据库自动诊断知识库（ADR）识别ORACLE_BASE目录，并妥善的帮助收集诊断事件的数据。

All Oracle components on the installation media are compliant with Optimal Flexible Architecture. Oracle Universal Installer places Oracle Database components in directory locations, assigning the default permissions that follow Optimal Flexible Architecture guidelines.

Oracle安装介质中的所有数据库组件都与OFA标准相兼容。OUI将会把将要安装的数据库组件放置到OFA指定的固定的目录，并且分配相应默认的权限。

Oracle recommends that you use Optimal Flexible Architecture, especially if the database is huge, or if you plan to have multiple databases.

Oracle公司官方建议我们使用OFA的标准目录结构，尤其是我们的数据库非常的庞大或者我们打算在同一目录下安装多数据库的时候。

2.Advantages of Multiple Oracle Homes and OFA

When you install Oracle database, you are installing a large application that your computer can support. Using multiple Oracle homes and Optimal Flexible Architecture provides many advantages when administering large databases. The following advantagesare important:

当我们安装管理的数据库将会很大时，使用OFA的多ORACLE_HOMS机制将会十分有用。

（1）Structured organization of directories and files, and consistent naming for database files simplify database administration.

（2）Distribution of I/O across multiple disks prevents performance bottle necks caused by multiple read or write commands issued simultaneously（同时）to a single drive.

（3）Distribution of applications across multiple disks safeguards against database failures.

（4）Login home directories are not at risk when database administrators add, move, or delete Oracle home directories.

（5）Multiple databases, of different versions, owned by different users can coexist concurrently.

（6）Software upgrades can be tested in an Oracle home in a separate directory from the Oracle home where your production database is located.

3.Implementing Optimal Flexible Architecture

3.1 File Systems

The following sections describe the conventions（公约） for mount points:

Numberof File Systems

NamingConventions

3.1.1 Number of FileSystems

To fully implement the Optimal Flexible Architecture recommendations for a database stored on file systems that are not striped or mirrored, you require at least three file systems located on separate physical devices.

为了完全实现OFA架构，在没有实现基础存储条带化和镜像的数据库环境中，Oracle建议将数据库存储在文件系统上，并且需要3个独立的物理设备。

3.1.2 Naming Conventions（命名约定）

Name all filesystem mount points using the syntax /pm, where p is a string constant（常数） and m is a unique fixed-length key (typically a two-digit number) used to distinguish each mount point. Forexample: /u01 and/u02, or /disk01 and /disk02.

文件系统的名字需要挂载到/pm目录下，这里的p代表一个字符串常量，m 代表一个定长的值，这个值通常由2个数字组成。 如：/u01,u02 或者 /disk01,/disk02。

3.2 Naming Directories(OFA的命名目录)

The following sections describe the naming conventions for directories that are compliant with the Optimal Flexible Architecture standard:

（1）OracleBase Directory Naming Convention

（2）NamingMount Points for Very Large Databases (VLDBs)

（3）Referring to Path Names

（4）OracleHome Directory Naming Convention

（5）Naming Subdirectories

 Note:

Ensure that the paths you select for Oracle software, such as the Oracle home path and the Oracle base path, use only ASCII characters. Because installation owner names are used by default for some paths, this ASCII character restriction applies to user names, file names, and directory names.

3.2.1 Oracle Base Directory NamingConvention

Oracle Base 目录的命名约定

The Oracle Base directory is the top level directory that you can use to install the various Oracle software products. You can use the same Oracle base directory for multiple installations. If different operating system users install Oracle software on the same system, then each user must create a separate Oracle base directory.

Oracle Base目录是最顶层的目录，我们可以在这个目录下安装多套Oracle。不同的数据库可以使用相同的ORACLE BASE 目录。如果在同一个操作系统下用不同的OS用户来安装Oracle，那么每个OS 用户必须创建独立的ORACLE BASE 目录。

Name Oracle base directories using the syntax /pm/s/u. TableD-1 describes the variables used in this syntax.

ORACLE base 目录使用如下格式:/pm/s/u。具体每个参数的含义参考下表：

Table D-1 Syntax for Naming Oracle BaseDirectories

For example, /u01/app/oracle is an Oracle base directory created by the oracle user and  /u01/app/applmgr is an Oracle base directory created by the applmgr user.

Placing Oracle base directories at the same level in the UNIX file system is advantageous because it enables you to refer to the collection of Oracle base directories on different mount points using a single pattern matching string, /*/app/*.

3.2.2 Naming Mount Points for VeryLarge Databases (VLDBs)

If each disk drive contains database files from one application and there are enough drives for each database to prevent I/O bottle necks, use the syntax /h/q/d for naming mount points. TableD-2 describes the variables used in this syntax.

如果每个磁盘存放一个应用的数据，从而来降低磁盘I/O的瓶颈，那么使用/h/q/d 的格式来挂载文件系统。具体参数含义参考下表：

Table D-2 Syntax for Naming Mount Points for Very Large Databases

For example, to allocate two drives exclusively for the test database, name the mount points /u01/app/oracle/oradata/test and /u02/app/oracle/oradata/test.

3.2.3 Referring to Path Names

Refer to explicit（显示的） path names only in files designed specifically to store them, such as the password file, /etc/passwd,and the Oracle oratab file. Refer to group memberships only in the /etc/group file.

3.2.4 Oracle Home Directory NamingConvention

Oracle Home 目录的命名约定

To help fulfill the Optimal Flexible Architecture requirement of simultaneously running multiple versions of Oracle software, install the software in a directory matching the pattern /pm/s/u/product/v/type_[n].

为了保证多个版本的数据库同时运行，OFA的目录需要按照如下格式:/pm/s/u/product/v/type_[n]. 具体含义参考下表：

 TableD-3 Syntax for Naming Oracle Home Directories

For example:

/u01/app/oracle/product/11.2.0/dbhome_1 indicates the Oracle home directory for the first installation of Oracle Database on this system.

The ORACLE_HOME environment variable is set to the Oracle home directory.

3.2.5 Naming Subdirectories

To facilitate the organization of administrative data, Oracle recommends that you store database-specific administration files in subdirectories matching the pattern /h/admin/d/a/, where h is the Oracle base directory, d is the database name (DB_NAME), and a is a subdirectory for specific types of database administration files. TableD-4 describes the database administration file subdirectories.

oracle 推荐的子目录使用如下格式：/h/admin/d/a, 这里h 是OracleBase，d 代表实例名，a 代表不同的类型。