I was trying to apply EBS R12 patch on ORACLE_HOME(10.1.2) application node and got the below issue because of inventory issue.


opatch lsinventory
Oracle Interim Patch Installer version
Copyright (c) 2011 Oracle Corporation. All Rights Reserved..
Oracle recommends you to use the latest OPatch version
and read the OPatch documentation available in the OPatch/docs
directory for usage. For information about the latest OPatch and
other support-related issues, refer to document ID 293369.1
available on My Oracle Support (https://myoraclesupport.oracle.com)
Cannot open the file: /etc/oraInst.loc
Please use -invPtrLoc option and specify the correct file for OPatch to look for central inventory.

ERROR: OPatch failed because of Inventory problem.


The cause of the error is due to inventory pointer file /etc/oraInst.loc not present in the default location
In Oracle Applications Release 12.x , if oraInst.loc is not present in the default location it will be present in the following locations

Database Tier :

<RDBMS $ORACLE_HOME>/oraInst.loc
<RDBMS $ORACLE_HOME>/admin/oui/$CONTEXT_NAME/oraInst.loc

Applications Tier :

Tools $ORACLE_HOME/oraInst.loc


Please check if the file oraInst.loc is present in ORACLE_HOME to which the patch is being applied

opatch lsinventory -invPtrLoc $ORACLE_HOME/oraInst.loc

Run the patch as below
cd patch directory
opatch apply -invPtrLoc $ORACLE_HOME(10.1.2)/oraInst.loc