Rawat -
The impact of auditing isn't that high.
It does depend on how much auditing you turn.
File access logging will be a bit more load.
cifs.audit.saveas specifies the location for the log files:
cifs.audit.saveas
Specifies the active event log file. The file must be in an existing directory in a network share.
You may wish to look at all of the cifs.audit option definitions before turning on auditing.
They're all documented in the 'options' man page:
https://library.netapp.com/ecmdocs/ECMP1511537/html/man1/na_options.1.html
I hope this response has been helpful to you.
At your service,
Eugene E. Kashpureff, Sr.
Independent NetApp Consultant http://www.linkedin.com/in/eugenekashpureff
Senior NetApp Instructor, IT Learning Solutions http://sg.itls.asia/netapp
(P.S. I appreciate 'kudos' on any helpful posts.)