Samba 4rc3 join to existing domain errors // Kerberos related ?

Joe Comeaux joe.comeaux at
Fri Oct 26 09:34:00 MDT 2012

> > > From: "Matthieu Patou" Wednesday, October 24, 2012 11:45:34 PM
> >
> > > What worries me much with your provision is the
> > > tdb_mmap failed for size -39583744 (Cannot allocate memory)

> From: "Andrew Bartlett" <abartlet at> Thursday, October 25, 2012 9:35:02 PM
> I still don't like the tdb_mmap error. Before doing anything more,
> find
> out why that's happening.

I'm trying to find out why that's happening, but dont really have an idea of what I should be doing to find out why. I've been searching for more information on the tdb_mmap, and i've found a few things, dont know which applies.

One post made mention of existing libpam ubuntu packages causing a conflict, so i confirmed there were no samba related packages installed.

Another post references /proc/<pid>/limits "max address space", which is currently unlimited.

I found a post mentioning adding "user mmap = no" entry in smb.conf, but that was from 2009. Is that still an option for samba4? Is that what I should do to remedy this particular error?

It seems that the posts i'm finding where there is a tdb_mmap failed with a cannot allocate memory message have something to do with the relationship between samba and pam and other packages that rely on pam ( like vsftpd ).
Perhaps the base OS version, or the fact it's running as a VM has something to do with this?

A few weeks back, there was a post mentioning "Moving a s4 DC to a different host". I'm not opposed to doing this, but that particular process involved joining a new host to the domain, which is what I'm having trouble with.
In my situation, it's actually easier to compile samba on a new machine and just transition the samba database as a whole to a new machine ( and have that machine take over the original IP address ), but I dont know what side effects this would cause.

I dont know what direction to go in trying to resolve the tdb_mmap error. I can't imagine that being a virtual machine would be causing the error, but is it worthwhile to set up a stand alone computer with the same OS version, and just copy the /usr/local/samba directory over to it, and run samba on it to see if the error remains?
Would upgrading to samba rc3 have any effect, or should I evaluate upgrading the OS?


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