Dell PowerVault 720N Command Reference Manual page 182

options cifs.trace_login on
If user jdoe attempts to log in, messages like the following
appear on the console:
Mon Jan 4 15:21:38 PST [CIFSAuthen]: Login attempt by DELL\
from SMITH-PC
Mon Jan 4 15:21:38 PST [CIFSAuthen]: User authenticated by DC
Mon Jan 4 15:21:38 PST [CIFSAuthen]: PC user name maps to UNIX
user smith
Mon Jan 4 15:21:38 PST [CIFSAuthen]: Unix user set to root by
wafl.nt_admin_priv_map_to_root
Mon Jan 4 15:21:38 PST [CIFSAuthen]: Login accepted
options cifs.trace_login off
jdoe