OPatch Fails for not Finding the 'fuser' Command

OPatch fails when it is unable to locate the fuser command.

OPatch fails with the following error on the command line:

Verifying environment and performing prerequisite checks...
Prerequisite check "CheckActiveFilesAndExecutables" failed.
The details are:
Exception occured : fuser could not be located:
UtilSession failed: Prerequisite check "CheckActiveFilesAndExecutables" failed.
Log file location: <PATH>/fmw/cfgtoollogs/opatch/opatch20xx-0x-20_11-40-12AM_1.log

Following options are available to resolve this issue:

Pass argument for OPatch to ignore fuser and continue with patching:

1. Set the environment variable OPATCH_NO_FUSER=true. Setting this variable to "true" informs OPatch to skip the check for active executables.
2. Shut down the WebLogic instances.
3. Run the OPatch utility.

Set a temporary fuser:

1. Set /tmp in your PATH.
2. Create an empty file named "fuser".
3. Shut down the WebLogic instances.
4. Run the OPatch utility.

Install the 'fuser' utility:

1. Install the 'fuser' utility on the machine (contact your OS Admin).
2. Ensure that 'fuser' is located under /sbin/fuser or /bin/fuser.
3. Shut down the WebLogic instances.
4. Run the OPatch utility.