dracmc-telnet - External stonith plugin for HAv2 (http://linux-ha.org/wiki)
                Connects to Dell Drac/MC Blade Enclosure via a Cyclades
                terminal server with telnet and switches power of named
                blade servers appropriatelly.

Description:
    Dell offers the Drac/MC in their blade enclosures.  The
Drac/MC can be accessed in different ways.  One way to interface to it
is to connect the blade enclosure's Drac/MC serial port to a Cyclades
terminal server.  You can then access the Drac/MC via telnet via the
Cyclades.  Once logged in, you can use 'help' to show all available
commands.  With the 'serveraction' command, you can control both
hard and soft resets as well as power to a particular blade.  The
blades are named 'Server-X', where 'X' is a number which corresponds
to the blade number in the enclosure.  This plugin allows using the
Drac/MC with stonith.  It uses python's standards 'telnetlib' library
to log in and issue commands.  The code is very similar to the original
ibmrsa-telnet plugin released by Andreas and was quite easy to
modify for this application.
    One complication is that the Cyclades only allows one active
connection.  If someone or something has a connection active, the
terminal server closes the new attempted connection.  Since this
situation can be common, for example if trying to stonith two blades
or when the plugin is started by multiple cluster nodes, there is a
built in retry mechanism for login.  On 10 retries, the code gives up
and throws.
    When running this resource, it is best to not run it as a clone,
rather as a normal, single-instance resource.  Make sure to create a
location constraint that excludes the node that is to be fenced.

Required parameters:
 nodename:      The name of the server you want to touch on your network
 cyclades_ip:   The IP address of the cyclades terminal server
 cyclades_port: The port for telnet to access on the cyclades (i.e. 7032)
 servername:    The DRAC/MC server name of the blade (i.e. Server-7)
 username:      The login user name for the DRAC/MC
 password:      The login password for the DRAC/MC

Example configuration

These are examples: you should adjust parameters, scores and
timeout values to fit your environment.

crm shell:

   primitive fence_node1 stonith:external/dracmc-telnet \
            nodename=node1 cyclades_ip=10.0.0.1 cyclades_port=7001 \
            servername=Server-1 username=USERID password=PASSWORD \
            op monitor interval="200m" timeout="60s"
   location loc-fence_node1 fence_node1 -inf: node1

XML:

<?xml version="1.0" ?>
<cib>
    <configuration>
        <resources>
            <primitive id="r_stonith-node01" class="stonith" type="external/dracmc-telnet" provider="heartbeat" resource_stickiness="0">
                <operations>
                    <op name="monitor" interval="200m" timeout="60s" prereq="nothing" id="r_stonith-node01-mon"/>
                    <op name="start" timeout="180" id="r_stonith-node01-start"/>
                    <op name="stop" timeout="180" id="r_stonith-node01-stop"/>
                </operations>
                <instance_attributes id="r_stonith-node01">
                    <attributes>
                        <nvpair id="r_stonith-node01-nodename" name="nodename" value="node01"/>
                        <nvpair id="r_stonith-node01-cyclades_ip" name="cyclades_ip" value="192.168.0.1"/>
                        <nvpair id="r_stonith-node01-cyclades_port" name="cyclades_port" value="7032"/>
                        <nvpair id="r_stonith-node01-servername" name="servername" value="Server-7"/>
                        <nvpair id="r_stonith-node01-username" name="username" value="USERID"/>
                        <nvpair id="r_stonith-node01-password" name="password" value="PASSWORD"/>
                        <nvpair id="r_stonith-node01-type" name="type" value="dellblade"/>
                    </attributes>
                </instance_attributes>
            </primitive>
        </resources>
        <constraints>
            <rsc_location id="r_stonith-node01_prefer_node02" rsc="r_stonith-node01">
                <rule id="r_stonith-node01_prefer_node02_rule" score="50">
                    <expression attribute="#uname" id="r_stonith-node01_prefer_node02_expr" operation="eq" value="node02"/>
                </rule>
            </rsc_location>
        </constraints>

    </configuration>
</cib>