open-minded information technology | good for business

Using a Linux samba server as an NT-style Domain controller (PDC) requires that you create a machine account in both the /etc/passwd file and the /etc/samba/smbpasswd file. There is a way to have machines automatically create their accounts (with proper setup in /etc/samba/smb.conf file and NOT covered here), or you can create machine accounts as follows:

useradd -g 100 -d /dev/null -c machinename -s /bin/false machinename$
passwd -l machinename$
smbpasswd -a -m machinename

Note: the $ at the end of the useradd and the passwd commands is mandatory and must not appear at the end of the smbpasswd cmd. machinename is the PC's windows machine name.

Note: you can create a linux shell script to create a machine account. The script should look like:

#!/bin/sh
# addmachine
# add samba machine account to passwd and smbpasswd files

# 

#remove any $ specified on the command line (we will add it when required!)... 

machinename=`echo $1|sed 's/\$//g'`

#set the machinegroup

machinegroup=600
/usr/sbin/useradd -g $machinegroup -d /dev/null -c $machinename -s /bin/false $machinename$
passwd -l $1$
smbpasswd -a -m $1

This file needs to be executable:

chmod 711 addmachine.

It is then invoked as:

addmachine machinename

(e.g. addmachine mypc1)

When you are done, you will see a line in /etc/passwd for machinename$ and a line in /etc/samba/smbpasswd for machinename$

N.B. If you just run useradd without setting the group number to 100, the default dir to the bit bucket (/dev/null) and the default login shell to /bin/false (so that no one can explicitly log into this account and run programs as a regular user), then you will have accounts that people could log into without a password being set. This is not a good idea in general because people could guess the account from knowing PC machine names.