The "nullok" option on instructs the pam_unix.so module to allow a blank password (which is not the default). Ref: http://linux.die.net/man/8/pam_unix
Why is this necessary to enable null passwords under pam_unix.so within the /etc/pam.d/vmtoolsd configuration file? Can this option be removed?
The default /etc/pam.d/vmtoolsd file is:
#%PAM-1.0
auth sufficient pam_unix2.so shadow nullok
auth sufficient pam_unix.so shadow nullok
auth required pam_unix_auth.so shadow nullok
account sufficient pam_unix2.so
account sufficient pam_unix.so
account required pam_unix_acct.so
Thank you in advance.