FDPSTP failed due to ORA-20100: Error: FND_FILE failure. Unable to create file, oXXXXXXXX.tmp in the directory, /usr/tmp

A TEST instance was already up and running and I created another production clone on the same server/machine. Once the services of both the instances  

The concurrent programs were completing in error and when checked the log files, the following error message was there:

ORACLE error 20100 in FDPSTP

Cause: FDPSTP failed due to ORA-20100: Error: FND_FILE failure. Unable to create file, o0031866.tmp in the directory, /usr/tmp.

You will find more information in the request log.

ORA-06512: at "APPS.FND_FILE", line 417

When investigated, I found that both the instnaces were creating .tmp files in /usr/tmp directory with the same name. This error was being thrown when one instance was trying to create .tmp file and a file with the same name was already created by the other instance.

• To resolve the issue I shutdown both the apps and db services of one instance.
• Created a directory 'temp' in '/usr/tmp' and changed the ownership of this dir to user owner of this instance 
• Logon to database as sysdba
• Create pfile from spfile
• modified UTL_FILE_DIR parameter's first entry from '/usr/tmp' to '/usr/tmp/temp'
• Created spfile from pfile
• Brought up the db and listener
• Now modified the $APPLPTMP variable in TEST_oratest.xml file from '/usr/tmp' to '/usr/tmp/temp'
• Run the autoconfig on apps tier/node
• Brought up the apps services
• Retested the issue and it was resolved