UtilSession failed: Prerequisite check "CheckActiveFilesAndExecutables" failed while applying patch

While applying 12c patch, it failed with below error

UtilSession failed: Prerequisite check "CheckActiveFilesAndExecutables" failed while applying patch

[root test.db.com] /oracle/home/oracle$ opatchauto apply /oracle/archivelog/patch/20132450 -ocmrf /oracle/archivelog/patch/unconfig_GI.rsp -nonrolling
OPatch Automation Tool
Copyright (c) 2015, Oracle Corporation.  All rights reserved.

OPatchauto version : 12.1.0.1.5
OUI version        : 12.1.0.2.0
Running from       : /oracle/product/grid/12.1.0

opatchauto log file: /oracle/product/grid/12.1.0/cfgtoollogs/opatchauto/20132450/opatch_gi_2015-02-24_03-25-09_deploy.log

Parameter Validation: Successful

Grid Infrastructure home:
/oracle/product/grid/12.1.0
RAC home(s):
/oracle/product/db/12.1.0

Configuration Validation: Successful

Patch Location: /oracle/archivelog/patch/20132450
Grid Infrastructure Patch(es): 19769473 19769479 19769480 19872484
RAC Patch(es): 19877336 19769479 19769480

Patch Validation: Successful

Stopping RAC (/oracle/product/db/12.1.0) ... Successful

Applying patch(es) to "/oracle/product/db/12.1.0" ...
Command "/oracle/product/db/12.1.0/OPatch/opatch napply -phBaseFile /tmp/OraDB12Home1_patchList -local  -invPtrLoc /oracle/product/grid/12.1.0/oraInst.loc -oh /oracle/product/db/12.1.0 -silent -ocmrf /oracle/archivelog/patch/unconfig_GI.rsp" execution failed:
UtilSession failed: Prerequisite check "CheckActiveFilesAndExecutables" failed.

Log file Location for the failed command: /oracle/product/db/12.1.0/cfgtoollogs/opatch/opatch2015-02-24_03-26-10AM_1.log

For more details, please refer to the log file "/oracle/product/grid/12.1.0/cfgtoollogs/opatchauto/20132450/opatch_gi_2015-02-24_03-25-09_deploy.debug.log".

Apply Summary:

Following patch(es) failed to be installed:
GI Home: /oracle/product/grid/12.1.0: 19769473, 19769479, 19769480, 19872484
RAC Home: /oracle/product/db/12.1.0: 19877336, 19769479, 19769480

opatchauto failed with error code 2.


Checking the log it shows that

[Feb 24, 2015 3:26:17 AM]    Finish fuser command /sbin/fuser /oracle/product/db/12.1.0/lib/libclntsh.so.12.1 at Tue Feb 24 03:26:17 PST 2015
[Feb 24, 2015 3:26:17 AM]    Start fuser command /sbin/fuser /oracle/product/db/12.1.0/lib/libasmclntsh12.so at Tue Feb 24 03:26:17 PST 2015
[Feb 24, 2015 3:26:17 AM]    Finish fuser command /sbin/fuser /oracle/product/db/12.1.0/lib/libasmclntsh12.so at Tue Feb 24 03:26:17 PST 2015
[Feb 24, 2015 3:26:17 AM]    Following executables are active :
                             /oracle/product/db/12.1.0/lib/libclntsh.so.12.1
[Feb 24, 2015 3:26:17 AM]    Prerequisite check "CheckActiveFilesAndExecutables" failed.
                             The details are:


                             Following executables are active :
                             /oracle/product/db/12.1.0/lib/libclntsh.so.12.1
[Feb 24, 2015 3:26:17 AM]    OUI-67073:UtilSession failed: Prerequisite check "CheckActiveFilesAndExecutables" failed.
[Feb 24, 2015 3:26:17 AM]    Finishing UtilSession at Tue Feb 24 03:26:17 PST 2015
[Feb 24, 2015 3:26:17 AM]    Log file location: /oracle/product/db/12.1.0/cfgtoollogs/opatch/opatch2015-02-24_03-26-10AM_1.log
[Feb 24, 2015 3:26:17 AM]    Stack Description: java.lang.RuntimeException: Prerequisite check "CheckActiveFilesAndExecutables" failed.
[Feb 24, 2015 3:26:17 AM]    StackTrace: oracle.opatch.OPatchSessionHelper.runApplyPrereqs(OPatchSessionHelper.java:6516)
[Feb 24, 2015 3:26:17 AM]    StackTrace: oracle.opatch.opatchutil.NApply.process(NApply.java:1617)


Reason:

Some one is accessing Oracle library

Solution:

Using fuser, find who is accessing and kill it.

[root test.db.com] /oracle/home/oracle$ fuser  /oracle/product/db/12.1.0/lib/libclntsh.so.12.1
/oracle/product/db/12.1.0/lib/libclntsh.so.12.1: 112053m


[root test.db.com] /oracle/home/oracle$ ps -ef|grep 112053
oracle   112053 111991  0 Feb23 pts/0    00:00:00 sqlplus

[root test.db.com] /oracle/home/oracle$ kill -9 112053