About Oracle Base Homes

In a read-only ORACLE_HOME, the user-specific files, instance-specific files, and log files reside in a location known as the ORACLE_BASE_HOME.

Starting with Oracle Database 21c, the only available configuration is a read-only ORACLE_HOME where ORACLE_BASE_HOME and ORACLE_BASE_CONFIG are located separately from ORACLE_HOME.

In a read-only ORACLE_HOME, the ORACLE_BASE_HOME directory is not co-located with ORACLE_HOME but is located at ORACLE_BASE\homes\HOME_NAME.

Where, HOME_NAME is the internal name for ORACLE_HOME.

For example, the networking directories network\admin, network\trace, and network\log are located in the ORACLE_BASE_HOME directory. In a read-only ORACLE_HOME, the networking directories are located in ORACLE_BASE\homes\HOME_NAME.

To print the ORACLE_BASE_HOME path, run the orabasehome command from the %ORACLE_HOME%\bin directory:
C:\> set ORACLE_HOME=C:\app\oracle\product\21.0.0\dbhome_1
C:\> cd %ORACLE_HOME%\bin
orabasehome

For example:

orabasehome
C:\app\oracle\homes\OraDB21Home1

Where, C:\app\oracle is ORACLE_BASE and OraDB21Home1 is HOME_NAME