Samba 3.0rc1 and Unix accounts

John H Terpstra jht at
Mon Aug 18 18:25:18 GMT 2003

On Mon, 18 Aug 2003, Tom Alsberg wrote:

> Hello.
> I got to install Samba 3.0rc1 (specifically, checked out from CVS with
> the SAMBA_3_0 tag today) and thought to test it a bit.  Had a little
> problem with tdbsam.
> I put passdb backend = tdb in smb.conf, not sure why, actually, since

	passwd backend = tdbsam, guest

This is covered extensively in the Samba-HOWTO-Collection.pdf that ships
in the docs directory of the samba-3.0.0 RC1 tarball.

> I thought that would be the default having read what I did in the
> example smb.conf
> By default, on a fresh install and first use, passdb.tdb does not
> exist.  So smbd (pdb_tdb) creates it on first request.  But for some
> reason, on subsequent requests, opening the TDB fails.  I don't know
> much about TDB, but the file exists (although its size is zero after
> it was created - shouldn't it have some internal tdb data and a few
> identifiying blocks even for an empty database?  Is this normal, or is
> the problem already before this?), and after I added a bit more to the
> debugging message, I see errno is Input/output error...
> Any idea why this is?  Is something wrong here with what I did (this
> is quite a clean install)?

To list the contents of this file do:
	tdbdump passdb.tdb

> A few other questions here:
> The example smb.conf says that tdbsam is now the current generic
> passdb backend and that smbpasswd is only kept for compatibility.  Yet
> for some reason, it seems that unless specifying it explicitly in
> smb.conf, smbpasswd is still used.  Why is that?

Backwards compatibility with Samba-2.x.

> Which is the exact code deciding which passdb backend to use (since
> there is no default in loadparam)?

No sure I understand your question.

> When (meaning during the server's lifetime - what events cause it, and
> where is it in the code) are passdb.tdb or smbpasswd changed by smbd?
> I recall it happening, but am not quite sure yet.  Basically unless
> using CIFS based some remote management/administration facilities
> (user manager or whatever), I cannot think right now why it would be
> modified for normal stuff (users and groups) except by the smbpasswd
> utility or whatever.

Covered int he HOWTO document. The tools that change (update) passdb.tdb
(or smbpasswd) are:

	smbd via the useradd/userdel scripts.

- John T.
John H Terpstra
Email: jht at

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