opatch auto failed, Missing command :fuser, Shared storage check failed on nodes "orahost2,orahost1"

opatch atuo failed, Missing command :fuser while opatch auto in oracle RAC 

environment.

Logfile:/u01/app/grid/11.2.0.4/cfgtoollogs/opatchauto2017-06-02_00-08-04.log

Message in logfile

Checking shared storage accessibility...

 "/u01/app/oracle/product/11.2.0.4/dbhome_1" is not shared

 Shared storage check failed on nodes "orahost2,orahost1"

Check in the same log you may get the prerequisite check failed due to fuser missing as below

Verifying environment and performing prerequisite checks...

 Prerequisite check "CheckSystemCommandAvailable" failed.

 The details are:

Reason: Failed during Analysis: CheckSystemCommandsAvailable Failed, [ Prerequisite Status: FAILED, Prerequisite output:
The details are:
Missing command :fuser]

 Missing command :fuser

Solution:

yum install psmisc

Now rerun the auto patch.