Following active executables are not used by opatch process : bin/oracle

 Problem:

When applying an interim patch on a 19c ORACLE_HOME using "opatch apply" command, I get this error:

 Prerequisite check "CheckActiveFilesAndExecutables" failed.
The details are:

Following active executables are not used by opatch process :
/u01/oracle/19.5/bin/oracle

Following active executables are used by opatch process :

UtilSession failed: Prerequisite check "CheckActiveFilesAndExecutables" failed.
Log file location: /u01/oracle/19.5/cfgtoollogs/opatch/opatch2022-03-03_15-39-23PM_1.log

OPatch failed with error code 73

Analysis:

Oracle binary file is being used by a process or session. Which indicates that there are services under ORACLE_HOME are still up and running.

Solution:

1- Make sure you properly shut down all Oracle services running from the ORACLE_HOME that is being patched.

2- Kill the processes that remain accessing ORACLE_HOME which will be patched: 

Caution: fuser command will not show only the process accessing ORACLE_HOME but will show all processes accessing the filesystem from which ORACLE_HOME is running,  i.e. if you have ORACLE Home and GRID Home running from same filesystem, below command will show all processes accessing both ORACLE_HOME and GRID_HOME.

# fuser -v -m $ORACLE_HOME

Then validate the list and kill the PIDs running from ORACLE_HOME.