Samba and PostgreSQL

Please note: This is a very short howto, so dont expect any detailed explanations.

Samba can use PostgreSQL as a backend for storing user specific data such as login name, password, login script, home dir etc. This is possibly what you want if you are running Samba as PDC in a Windows NT/2000 domain environment because it is more convienient to have a sql database than flat files for this.

Installation steps:

• Make a backup of your current configuration files and your data, especially (but not limited to) smb.conf and any *.tdb files!
• download and install PostgreSQL, make sure that you have also installed the header files and the libraries
• download and install Samba, you should pass the --with-expsam=pgsql parameter to configure; if have installed PostgreSQL in a non standard location, you should also pass the --with-pgsql-prefix= parameter
• consider creating a new database user for use with samba (lets call it my_samba_user)
• give that user a password (my_samba_password)
• create a table (eg. my_samba_table) using this definition
• grant everything on this table to your samba user (well, SELECT, INSERT, UPDATE and DELETE ought to be enough, eg. if you leave DELETE, you wont be able to delete any user through Samba or the NT user manager :-))
• update your smb.conf:

  passdb backend = pgsql:my_pgsql
  my_pgsql:pgsql user = my_samba_user
  my_pgsql:pgsql password = my_samba_password
  my_pgsql:pgsql database = <name of your database cluster>
  my_pgsql:table = my_samba_table
  

• if you have any user data in a tdbsam or even a smbpasswd file, you can use pdbedit to get them into the sql database: pdbedit -i tdbsam: -e pgsql:my_pgsql (Note: this is the nastiest part and may fail as it did for me when I switched my PDC from a x86-Linux PC (LSB, little endian) to an Ultrasparc-Linux workstation (MSB, big endian))
• start PostgreSQL and Samba (in that order)
• hopefully finished, check with pdbedit -Lv

If anything goes wrong, then turn on logging for Samba and PostgreSQL. The psql and the pdbedit tools are your friends.

You might encounter situations where a workstation's hostname is stored in lowercase characters in the database while the workstation sends an uppercased string to authenticate itself. Maybe this is a bug in the pgsql backend. You can manually fix it by doing a sql command like UPDATE my_samba_table SET username='HOSTNAME$' WHERE username='hostname$'; with psql.