INST TOP directory

Instance top contains all the config files, log files, ssl certificates, document root etc. Addition of this directory makes the middle-tier more organized, since data is kept separate from config/log files. Another advantage is that, multiple instances can easily share the same middle tier. To create a new instance that shares an existing middle-tier, just create a new instance_top with proper config files and NFS mount the middle tier in the server.

INSTANCE TOP - STRUCTURE 

$INST_TOP: /oracle/inst/apps/SID_hostname

/admin /scripts  ADMIN_SCRIPTS_HOME: Find all AD scripts here

/appl  APPL_CONFIG_HOME. For standalone envs, this is set to $APPL_TOP

/fnd/12.0.0/secure FND_SECURE: dbc files here

 /admin All Env Config files here

/certs SSL Certificates go here

/logs LOG_HOME: Central log file location. All log files are placed here (except adconfig)

/ora ORA_CONFIG_HOME

    /10.1.2 'C' Oracle home config, Contains tnsnames and forms listener servlet config files

    /10.1.3 Apache & OC4J config home, Apache, OC4J and opmn

This is the 'Java' oracle home configuration for OPMN, Apache and OC4J

/pids Apache/Forms server PID files here

/portal Apache's DocumentRoot folder