[Samba] Simple Samba PDC - tdbsam limitations?

simo idra at samba.org
Fri Dec 21 19:55:12 GMT 2007

On Fri, 2007-12-21 at 13:48 -0500, Ryan Novosielski wrote:
> Hash: SHA1
> Charles Marcus wrote:
> > Charles Marcus, on 12/21/2007 8:06 AM, said the following:
> >> What are the limitations of the tdbsam backend, with respect to
> >> performance and the number of workstations/users it can reasonably be
> >> expected to support?
> > 
> > Never mind - of course this is well documented in the most excellent
> > 'The Official SAMBA-3 HOWTO and Reference Guide'...
> > 
> > For anyone curious - it is not generally recommended to use the tdbsam
> > backend for sites with 250+ users, but this is only because these sites
> > likely will be spread out and require BDCs and multiple servers...
> > 
> > They specifically mention one site using the tdbsam backend with 4,500+
> > users with no performance problems whatsoever...
> > 
> > Sorry for the noise.
> This is extremely timely for me, since I was looking into this subject
> just this morning.
> I have about 11,500 users on an smbpasswd file! :-o This does not work
> very well, and we recently reached a breaking point. I looked into
> tdbsam, figuring that that might be the easy way to go (I do not need
> replication, as this backend is running a computer lab, not 11,500
> concurrent users). The fact that my setup is two orders of magnitude
> larger than the recommendation for tdbsam gives me pause.
> Can anyone comment on this? I'm sorta in an emergency situation, not a
> design situation... I'm almost looking at MySQL because that is
> something that I could reasonably deploy in the next 48 hours. LDAP
> would require at least some substantial reading for me, I'd think. Maybe
> not.

If you do  not need to replicate user information elsewhere tdbsam is
the fastest backend you can get.

The recommendation about 250+ users has more to do with network
topologies usually implemented when you get around these numbers, and
has nothing to do with the scalability of the backend itself.


Simo Sorce
Samba Team GPL Compliance Officer <simo at samba.org>
Senior Software Engineer at Red Hat Inc. <ssorce at redhat.com>

More information about the samba mailing list