Ubuntu – Samba: session setup failed: NT_STATUS_LOGON_FAILURE

This might help. I do something similar, but only one share is open to the group's users. Other shares are read-only except for a single maintainer user. The [global] section of my smb.conf is almost identical to yours, except I don't use the force create/directory mode directives (in my case, they'd interfere with the other shares).

Here's the share definition:

[shared stuff]
        comment = blah, blah, etc
        path = /path/to/share
        write list = @sambagroup
        force group = +sambagroup
        read only = yes
        directory mask = 0775
        create mask = 0664
        guest ok = yes
        invalid users = root
        case sensitive = True
        default case = lower
        preserve case = yes
        short preserve case = yes

The important stuff here are these:

• read only = yes -- by default, read only.
• guest ok = yes -- guests can browse.
• write list = @sambagroup -- Authenticated members of sambagroup can write.
• force group = +sambagroup -- The + means that the force only applies to existing members of sambagroup. They're already the only ones who can write. I think, without the +, guest is given sambagroup credentials, which is not wanted (particularly with the write list directive above).
• directory mask = 0775
• create mask = 0664

These do exactly what you want yours to do: "drwxrwxr-x" on directories, "rwxrwxr-x" on files, and newly created files are owned by the user and sambagroup. The maintainers of the other shares get the same permissions as everyone else when working in shared stuff, and permissions & groups are normal when they work in the other shares.

My smb.conf has been working with only minor tweaks through several different versions of Samba, and currently is used with Samba 3.2.5. I never had it running on Ubuntu 8.04, but it ran on Ubuntu 7.04 for a long time before getting migrated to a recent Debian Lenny install.

SOLVED!!!!!!!!!!!

I have a script that was starting Samba (NMBD, SMBD) as well as OpenLDAP (SLAPD). It's an RC script that reads configuration data from a file to determine, among other things, which processes are already running or if a dependent process fails to start, etc... Here is a snippet of the relevant part in the script. The last line copies a version of the nsswitch.conf into place that specifies to use LDAP lookups.

while [ $i -lt $MAXPROCS ];
  do
   PID=${PROC[$i]}
   StartProc $PID

   if test $? != 0; then
    echo "!!! Aborting Any Remaining Start-up Processes !!!"
    exit 1
   fi

  i=$(($i+1))
done

 cp /etc/rc.d/pozix/nsswitch.conf.ldap /etc/nsswitch.conf

And upon shutdown I was doing the following; notice I copy a nsswitch.conf file that has "noldap" entries in it.

while [ $i -lt $MAXPROCS ];
do
  PID=${PROC[$i]}
  StopProc $PID
  i=$(($i+1))
done

cp /etc/rc.d/pozix/nsswitch.conf.noldap /etc/nsswitch.conf

It turns out that in the start-up scenario, samba wants the nsswtich.conf content to have the ldap entries there prior to invocation. Here is what I did to fix my issues:

cp /etc/rc.d/pozix/nsswitch.conf.ldap /etc/nsswitch.conf

while [ $i -lt $MAXPROCS ];
  do
   PID=${PROC[$i]}
   StartProc $PID

   if test $? != 0; then
    cp /etc/rc.d/pozix/nsswitch.conf.noldap /etc/nsswitch.conf
    echo "!!! Aborting Any Remaining Start-up Processes !!!"
    exit 1
   fi

  i=$(($i+1))
done

In summary, it appears that how you start SMBD is just as important as when you start it. If you start SMBD when nsswitch.conf has no LDAP entries, you get a version of smbd running linked to nss_ldap.so thinking it should only rely upon /etc/passwd (if that is all that is in the nsswitch.conf file) and changing the nsswitch.conf contents after SMBD is running has no effect.

Hope this helps other system builders....