When you try to login to a user using su, you get "su: Authentication failure" message
su - myuser
Password:
su: Authentication failure
Resolution:
- Check if the password is expired -> # chage -l myuser
- Check the pam error: # more /etc/pam.d/login
- Check any error: # pam_tally2 --user=myuser
- If not "0" on the above, just reset: # pam_tally2 --user=pe1adm --reset
This will solve your problem.
