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<h1>Setting up clustered samba</h1>

It is assumed tou have already installed the ctdb version of samba and also installed, configured and tested CTDB.

<h2>Create a user account</h2>

First you need to initialise the Samba password database so that you have some user that can authenticate to the samba service.<br>
Do this by running:
<pre>
  smbpasswd -a root
</pre>

Samba with clustering must use the tdbsam or ldap SAM passdb backends (it must not use the default smbpasswd backend), or must be configured to be a member of a domain.<br>
The rest of the configuration of Samba is exactly as it is done on a normal system.<br><br>
See the docs on http://samba.org/ for details.

<h2>Critical smb.conf parameters</h2>

A clustered Samba install must set some specific configuration parameters
<pre>
  clustering = yes
  idmap backend = tdb2
  private dir = /a/directory/on/your/cluster/filesystem
</pre>

It is vital that the private directory is on shared storage. 

<h2>Using smbcontrol</h2>

You can check for connectivity to the smbd daemons on each node using smbcontrol
<pre>
  smbcontrol smbd ping
</pre>

<h2>Using Samba4 smbtorture</h2>

The Samba4 version of smbtorture has several tests that can be used to benchmark a CIFS cluster.<br>
You can download Samba4 like this:
<pre>
  svn co svn://svnanon.samba.org/samba/branches/SAMBA_4_0
</pre>
Then configure and compile it as usual.<br>
The particular tests that are helpful for cluster benchmarking are the RAW-BENCH-OPEN, RAW-BENCH-LOCK and BENCH-NBENCH tests.<br>
These tests take a unclist that allows you to spread the workload out over more than one node. For example:

<pre>
  smbtorture //localhost/data -Uuser%password  RAW-BENCH-LOCK --unclist=unclist.txt --num-progs=32 -t60
</pre>

The file unclist.txt should contain a list of server names in your cluster prefixed by //. For example
<pre>
 //192.168.1.1
 //192.168.1.2
 //192.168.2.1
 //192.168.2.2
</pre>

For NBENCH testing you need a client.txt file.<br>
A suitable file can be found in the dbench distribution at http://samba.org/ftp/tridge/dbench/


<h3>CTDB_MANAGES_SAMBA</h3>
This is a parameter in /etc/sysconfig/ctdb<br><br>
When this parameter is set to "yes" CTDB will start/stop/restart the local samba daemon as the cluster configuration changes.<br><br>
When this parameter is set you should also make sure that samba is NOT started by default by the linux system when it boots, e.g.
<pre>
  chkconfig smb off
</pre>
on a Redhat system and
<pre>
  chkconfig smb off
  chkconfig nmb off
</pre>
on a SuSE system.

Example:
<pre>
  CTDB_MANAGES_SAMBA="yes"
</pre>

It is strongly recommended that you set this parameter to "yes" if you intend to use clustered samba.

<h3>CTDB_MANAGES_WINBIND</h3>
This is a parameter in /etc/sysconfig/ctdb<br><br>
When this parameter is set to "yes" CTDB will start/stop/restart the local winbind daemon as the cluster configuration changes.<br><br>
When this parameter is set you should also make sure that winbind is NOT started by default by the linux system when it boots:
<pre>
  chkconfig winbind off
</pre>

Example:
<pre>
  CTDB_MANAGES_WINBIND="yes"
</pre>

It is strongly recommended that you set this parameter to "yes" if you
intend to use clustered samba in DOMAIN or ADS security mode.

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