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Joining SmartOS to an Active Directory domain

Why would you want to join SmartOS to an AD domain?

I am using SmartOS as both a file server for Windows clients and as a virtual machine host (hypervisor) running Windows Server and Linux VMs. The CIFS feature allows SmartOS to serve files to Windows clients from the GZ using just kernel code – no extra software required.  But SmartOS does not support the definition of users, groups, etc., in the GZ, so how can we implement any sort of security?  So it makes sense to utilize an Active Directory for this.  If you join the SmartOS GZ to an AD domain, CIFS can use the AD to authenticate users and check access control lists.

The AD doesn't have to be a Windows Server: it can be Samba4 running in a VM.

(By the way, an alternative approach for serving files to Windows clients is to install Samba3, in the GZ or in a OS zone.  While that involves another layer of software, it supports the SMB2 protocol [CIFS does not], so it's not clear how that would affect performance – it might improve it.  It also supports shared printers.  That approach is not documented here.)

Only the GZ can be joined to a domain.  And changes made to the GZ are not persistent.  So that complicates things a little.  Here is how to do it.

In the following examples...

  • My domain name is
  • My AD server is hostname samba-ad (, IP address
  • My SmartOS GZ is hostname smartos, IP address

First we will do everything interactively.

Edit /etc/hosts – insert your AD host (this step is helpful but not essential). Example:       localhost loghost    smartos   # my SmartOS GZ    samba-ad # my AD server

Edit /etc/resolv.conf – insert a domain line with your domain name, and a nameserver line pointing to your AD server. If your AD server is a VM, you may want a secondary nameserver that is always available. Example:

nameserver # my AD server
nameserver  # my 'always on' DNS

Edit /etc/krb5/krb5.conf. Example:

    default_realm = ALLENLAN.NET
        kdc =
        admin_server =
        kpasswd_server =
        kpasswd_protocol = SET_CHANGE
[domain_realm] = ALLENLAN.NET

And then:

cp /etc/ /etc/nsswitch.conf

Important: Make sure the SmartOS clock is synchronized to your AD server. This should be done by setting ntp_hosts in /usbkey/config. If you're doing this in a zone, you won't be able to change the clock since it comes from the global zone.

Then substitute your AD IP address or hostname in the first command, and your domain or OU administrator username in the last command:

sharectl set -p ads_site= smb
svcadm enable -r smb/server
smbadm join -u administrator

The 'smbadm join' command should return at least 5 lines of information showing that you are joined to the domain.  To further test the join, substitute a domain username in this command:

getent passwd

This should return information about the user.

Once this is working, we need to make all of the above changes persistent.  The /etc/ files will be overwritten by the next boot, and the idmap & smb/server services will start up not joined to a domain. So copy the modified /etc/ files someplace permanent.  I am saving them in /opt/custom/domain-join/

mkdir -p /opt/custom/domain-join
cd /etc
cp hosts resolv.conf nsswitch.conf krb5/krb5.conf /opt/custom/domain-join/
svccfg export -a smb/server > /opt/custom/domain-join/smb-server.exp
svccfg export -a idmap > /opt/custom/domain-join/idmap.exp

Let's make sure everything is still working.  Reboot the system, then perform the following commands:

svcadm disable idmap smb/server
cd /opt/custom/domain-join
cp hosts resolv.conf nsswitch.conf /etc/
cp krb5.conf /etc/krb5/
svccfg import idmap.exp
svccfg import smb-server.exp
svcadm enable idmap smb/server
smbadm list

Does it show the system is joined to the domain?  If so, good so far.

Finally we need an SMF service that will perform these steps for us on each boot.  The SMF XML itself is very basic, here is what the script looks like:

# - refresh the status of the domain join upon boot
set -o xtrace
. /lib/svc/share/
cd /
#PATH=/usr/sbin:/usr/bin; export PATH
case "$1" in
 /usr/sbin/svcadm disable idmap smb/server
 cp /opt/custom/domain-join/hosts /etc/
 cp /opt/custom/domain-join/resolv.conf /etc/
 cp /opt/custom/domain-join/krb5.conf /etc/krb5/
 cp /opt/custom/domain-join/nsswitch.conf /etc/
 /usr/sbin/svccfg import /opt/custom/domain-join/idmap.exp
 /usr/sbin/svccfg import /opt/custom/domain-join/smb-server.exp
 /usr/sbin/svcadm enable idmap smb/server ;;
 echo "Usage: $0 start"

If your AD is a VM running on this SmartOS, it's probably a good idea to wait for that VM to be fully up & running before performing the svccfg import command which restarts the smb/server service.