PAM
To use PAM, the linux-pam package itself must be installed as well as something for logging into the system that supports PAM. The login bundled with busybox does not support PAM. Instead, one of the following may be used:
- greetd plus any greeter
- login(1)provided by shadow-login
- login(1)provided by util-linux-login

 Warning: Login without PAM will still be possible. See #11730
ulimit
ulimit permissions can be changed via /etc/security/limits.conf. These will only apply if a PAM-compatible tool is used for logging in (as indicated above).