Dear all,
Autodir is for creating home directories and group directories much better then pam_mkhomedir as pam_mkhomedir does suffer some limitations like,
There are some applications which never need to authenticate users But they need home dirs -- for example mail servers configured to use home dirs for mail delivery and storage but not configured to use pam.
Some do use other ways to authenticate, bypassing pam all together.
Servers must be root so that pam can create home dirs. Otherwise make /home similar in permissions to /tmp
And there are other interesting features with Autodir like transparent backup for 24x7 online systems and many more.
Autodir uses autofs kernel module to transparently create home dirs And for more information check http://www.intraperson.com/autodir/
And here is Autodir-HOWTO http://prdownloads.sourceforge.net/intraperson/Autodir-HOWTO.html?download
Regards ramana