Without setting the above “pamlogin” parameters in the agentparm.txt, the agent does not log the user into the system to run the job.
Instead, the agent makes the system call "setuid" to change the owner of the running process.
This does not do any of the things that happen when a user logs in.
With “pamlogin” parameters set, we login with PAM and let the PAM modules determine how the login is handled and how to modify user permissions and/or environment.
The "su" PAM module is configured to act just like typing "su" at the command line.
When it is run by root, no password is required.
However, it is also configured to load the user's ulimit configuration values.