To understand how a patch is applied and to troubleshoot any problems with the application of a patch, you should review the log file for the OPatchAuto session.
The log file location is usually saved to the following directory or a subdirectory within this location:
ORACLE_HOME/cfgtoollogs/opatchauto/
Subdirectories within this location are identified by the patch number or by the command you ran.
The file name for each log file identifies the date and time it was executed. For example:
opatchauto2015-09-28_11-47-13AM.log
You can also locate the log file by viewing the output of the opatchauto command. The log file name and location is included in the output of the command. For example:
Session log file is /home/Oracle/products/fmw12c/cfgtoollogs/opatchauto/opatchauto2015-09-28_11-47-13AM.log