“Prerequisite check “CheckActiveFilesAndExecutables” failed error” While issueing opatch apply

Problem
While applying interim patch, I got Prerequisite check “CheckActiveFilesAndExecutables” failed error and resolved the issue with the help of fuser.

oracle@biasore>opatch apply
 Invoking OPatch 11.1.0.6.6

Oracle Interim Patch Installer version 11.1.0.6.6
 Copyright (c) 2009, Oracle Corporation.  All rights reserved.

Oracle Home       : /u01/app/oracle/product/11.2.0/dbhome_1
 Central Inventory : /u01/app/oraInventory
 from           : /etc/oraInst.loc
 OPatch version    : 11.1.0.6.6
 OUI version       : 11.2.0.1.0
 Log file location : /u01/app/oracle/product/11.2.0/dbhome_1/cfgtoollogs/opatch/opatch2013-03-05_23-47-17PM.log

Patch history file :
/u01/app/oracle/product/11.2.0/dbhome_1/cfgtoollogs/opatch/opatch_history.txt

Applysession applying interim patch '11678127' to OH '/u01/app/oracle/product/11.2.0/dbhome_1'
 Verifying environment and performing prerequisite checks...
 Prerequisite check "CheckActiveFilesAndExecutables" failed.
 The details are:

Following executables are active :
 /u01/app/oracle/product/11.2.0/dbhome_1/lib/libclntsh.so.11.1
 ApplySession failed during prerequisite checks: Prerequisite check "CheckActiveFilesAndExecutables" failed.
 System intact, OPatch will not attempt to restore the system

Recommended actions: OPatch needs to modify files which are being used by some processes.

OPatch failed with error code74

Cause
Something is using oracle library.
Solution
I had solved the issue first looking at the log file and saw that the inuse control made by fuser, this is also a clue for me to find who is using the library file.

oracle@biasore>/sbin/fuser /u01/app/oracle/product/11.2.0/dbhome_1/lib/libclntsh.so.11.1
 /u01/app/oracle/product/11.2.0/dbhome_1/lib/libclntsh.so.11.1: 29279m
 oracle@biasore>

oracle@biasore>ps -ef |grep 29279
  oracle   22813  3717  0 21:18 pts/13   00:00:00 grep 29279
Here I found some thing is running 29279 pid.
 oracle@biasore>kill -9 29279

After than I had successfully applied the patch.

This document describes how you can install the one-off patch for bug#  11678127 on your Oracle Database 11g Release 11.2.0.1.0
 
(1) Prerequisites
--------------------
Before you install or deinstall the patch, ensure that you meet the following requirements:
Note: In case of an Oracle RAC environment, meet these prerequisites on each of the nodes.

1. Ensure that the Oracle Database on which you are installing the patch or from which you are rolling back the patch is Oracle Database 11g Release 11.2.0.1.0.

2.      Oracle recommends you to use the latest version of OPatch. 
 If you do not have the latest version, then follow the instructions outlined in the My Oracle Support note 224346.1 available at:
 https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&id=224346.1 

3. Ensure that you set the ORACLE_HOME environment variable to the Oracle home of the Oracle Database.

4. Ensure that you set the PATH environment variable to include the location of the unzip executable, and the <ORACLE_HOME>/bin and the <ORACLE_HOME>/OPatch directories present in the Oracle home of the Oracle Database.

5. Ensure that you verify the Oracle Inventory because OPatch accesses it to install the patches. To verify the inventory, run the following command. If the command displays some errors, then contact Oracle Support and resolve the issue.
        $ opatch lsinventory 

6. Ensure that you shut down all the services running from the Oracle home.

Note:
 - For a Non-RAC environment, shut down all the services running from the Oracle home. 

(2) Installation
-----------------
To install the patch, follow these steps:
Note: In case of an Oracle RAC environment, perform these steps on each of the nodes.

1. Maintain a location for storing the contents of the patch ZIP file. In the rest of the document, this location (absolute path) is referred to as <PATCH_TOP_DIR>.

2. Extract the contents of the patch ZIP file to the location you created in Step (1). To do so, run the following command:
 $ unzip -d <PATCH_TOP_DIR> p11678127_112010_Linux-x86-64.zip

3. Navigate to the <PATCH_TOP_DIR>/11678127 directory:
 $ cd <PATCH_TOP_DIR>/11678127

4. Install the patch by running the following command:
 $ opatch apply

 Note:
 When OPatch starts, it validates the patch and ensures that there are no conflicts with the software already installed in the ORACLE_HOME of the Oracle Database. OPatch categorizes conflicts into the following types: 
 - Conflicts with a patch already applied to the ORACLE_HOME - In this case, stop the patch installation and contact Oracle Support Services.
 - Conflicts with a patch already applied to the ORACLE_HOME that is a subset of the patch you are trying to apply  - In this case, continue with the patch installation because the new patch contains all the fixes from the existing patch in the ORACLE_HOME. The subset patch will automatically be rolled back prior to the installation of the new patch.

5. Start the services from the Oracle home.

(3) Deinstallation
---------------------
To deinstall the patch, follow these steps:
Note: In case of an Oracle RAC environment, perform these steps on each of the nodes.

1. Navigate to the <PATCH_TOP_DIR>/11678127 directory:
 $ cd <PATCH_TOP_DIR>/11678127

2. Deinstall the patch by running the following command:
 $ opatch rollback -id 11678127

3. Start the services from the Oracle home.


(4) Bugs Fixed by This Patch
---------------------------------
The following are the bugs fixed by this patch:
  11678127: OCIDESCRIBEANY RETURNS ORA:24323 FOR AN OBJECT TYPE USE CASE