Redhat 5.1, 2.0.0 alpha, what advantage PAM?

[MATHOG at seqaxp.bio.caltech.edu]

Hi,

It appears that the CVS source builds by default to include PAM support on
RedHat 5.1, and there is some very cryptic (for somebody who had never
heard of PAM before last week) information in "packaging" about how to
configure it, but nothing particular useful about what PAM actually does
for you in this situation.  Also, while the Makefile has "-lpam" and the .h
file doesn't have it undef'd, none of the "pam" files in packaging
installed when I did "make install".  Which leads me to ask:

Is PAM on by default, or not, when you build the CVS tree in Redhat 5.1?

Can somebody explain (briefly) why a Samba domain controller, running on
RedHat 5.1, would want to use PAM? 

Previously we've been running 1.9.19 on an SGI, and that worked fine
as a primary domain controller pretty much out of the box, well, after
a third or fourth read of the NTdomain.txt file, anyway.  Conversely, the
current 2.0.0 alpha CVS sources build ok, and remote machines can connect
to a share using the domain username/password, but none of the workstations
in the domain will let a domain user login on the console when the new
server is the only one run (becomes the PDC).   A zero byte logfile is 
created, and that's it on the server end.  We've fallen back to having the
1.9.19 samba on an SGI server out NFS served user disk, which works, but
we'd really like to get the SGI out of the loop. 

Thanks,

David Mathog
mathog at seqaxp.bio.caltech.edu
Manager, sequence analysis facility, biology division, Caltech