Jean FrançoisMicouleau &author.jerry; Starting with Samba 3.0 alpha 2, new group mapping functionality is available to create associations between Windows SIDs and UNIX groups. The groupmap subcommand included with the net tool can be used to manage these associations. The first immediate reason to use the group mapping on a Samba PDC, is that the domain admin group &smb.conf; has been removed. This parameter was used to give the listed users membership in the "Domain Admins" Windows group which gave local admin rights on their workstations (in default configurations). When installing NT/W2K on a computer, the installer program creates some users and groups. Notably the 'Administrators' group, and gives to that group some privileges like the ability to change the date and time or to kill any process (or close too) running on the local machine. The 'Administrator' user is a member of the 'Administrators' group, and thus 'inherit' the 'Administrators' group privileges. If a 'joe' user is created and become a member of the 'Administrator' group, 'joe' has exactly the same rights as 'Administrator'. When a NT/W2K machine is joined to a domain, the "Domain Adminis" group of the PDC is added to the local 'Administrators' group of the workstation. Every member of the 'Domain Administrators' group 'inherit' the rights of the local 'Administrators' group when logging on the workstation. The following steps describe how to make samba PDC users members of the 'Domain Admins' group? create a unix group (usually in /etc/group), let's call it domadm add to this group the users that must be Administrators. For example if you want joe,john and mary, your entry in /etc/group will look like: domadm:x:502:joe,john,mary Map this domadm group to the "Domain Admins" group by running the command: root# net groupmap add ntgroup="Domain Admins" unixgroup=domadm The quotes around "Domain Admins" are necessary due to the space in the group name. Also make sure to leave no whitespace surrounding the equal character (=). Now joe, john and mary are domain administrators! It is possible to map any arbitrary UNIX group to any Windows NT group as well as making any UNIX group a Windows domain group. For example, if you wanted to include a UNIX group (e.g. acct) in a ACL on a local file or printer on a domain member machine, you would flag that group as a domain group by running the following on the Samba PDC: root# net groupmap add rid=1000 ntgroup="Accounting" unixgroup=acct Be aware that the rid parmeter is a unsigned 32 bit integer that should normally start at 1000. However, this rid must not overlap with any RID assigned to a user. Verifying this is done differently depending on on the passdb backend you are using. Future versions of the tools may perform the verification automatically, but for now the burden in on you. You can list the various groups in the mapping database by executing net groupmap list. Here is an example: root# net groupmap list System Administrators (S-1-5-21-2547222302-1596225915-2414751004-1002) -> sysadmin Domain Admins (S-1-5-21-2547222302-1596225915-2414751004-512) -> domadmin Domain Users (S-1-5-21-2547222302-1596225915-2414751004-513) -> domuser Domain Guests (S-1-5-21-2547222302-1596225915-2414751004-514) -> domguest For complete details on net groupmap, refer to the net(8) man page.