Directory Structures for Oracle RAC

Review this topic to understand the hierarchical directory tree of a sample Optimal Flexible Architecture (OFA)-compliant database for Oracle RAC.

Table B-1 Directory Structure for A Sample OFA-Compliant Environment

Directory	Description
`$ORACLE_BASE`	The default `ORACLE_BASE` directory, where the software owner is the `oracle` user. For example: `/u01/app/oracle`
`installation_type`	Type of installation under the Oracle base directory. For example, when installing Oracle Database 12c Release 2 (12.2), the value for installation type is `product/12.2.0/db`. For example: `/u01/app/oracle/product/12.2.0/db`
`$ORACLE_HOME`	The location in which the Oracle Database software is installed. You can also choose to add a counter, if you have multiple installations of the software. For example, if you are creating a second Oracle home for the Oracle Database 12c Release 2 (12.2) software, then the path is as follows: `/u01/app/oracle/12.2.0/db_home2` Note that the Oracle database home is under the Oracle base directory path. An Oracle Clusterware directory must not be under the Oracle base directory path where the database executable files are located.
`dbs`	The directory in which the local initialization parameter file is stored for the database.
`admin`	The administrative directory. Note that with Oracle Database 11g, `bdump`, `cdump`, and `udump` files are relocated to the directory associated with `ADR_BASE`. For example: `/u01/app/oracle/admin`
`db_unique_name`	The database unique name; this is the same as `dbname` when the database name is 8 or fewer characters in length. For example, if your database name is `sales`, the directory path is: /u01/app/oracle/admin/sales
`/hdump` `/pfile`	The dump destinations for database server.
`$ADR_BASE/bdump` `$ADR_BASE/cdump` `$ADR_BASE/udump`	Automatic Diagnostic Repository dump destination trace files. Note that this directory path is set by the initialization parameter `DIAGNOSTIC_DEST`, and that the path for the Automatic Data Repository must be located on a shared storage location available to all the nodes. By default, this path is a subset of the Oracle base directory, in the following path: `$ORACLE_BASE/diag/`
Oracle Grid Infrastructure for a cluster home (Grid home)	An OFA-compliant path for the Oracle Clusterware home. The default value is: `/u01/app/12.2.0/grid` During the Oracle Grid Infrastructure for a cluster installation, Oracle Clusterware and Oracle Automatic Storage Management (Oracle ASM) software is installed. The `root.sh` script changes permissions of all of the parent directories of the Oracle Clusterware home directory to grant write access only to the root user. Because of this, the Oracle Clusterware home directory must not be a subdirectory of the Oracle base directory.
`bin`	The subtree for Oracle Clusterware and Oracle ASM executable files.
`network`	The subtree for Oracle Net Services configuration files and utilities.