[Cluster-devel] cluster/fence/man fenced.8

[teigland@sourceware.org <teigland@sourceware.org>]

CVSROOT:	/cvs/cluster
Module name:	cluster
Changes by:	teigland at sourceware.org	2007-08-17 18:26:17

Modified files:
	fence/man      : fenced.8 

Log message:
	Outline the basic ideas of multiple methods and multiple devices.

Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/cluster/fence/man/fenced.8.diff?cvsroot=cluster&r1=1.6&r2=1.7

--- cluster/fence/man/fenced.8	2007/08/16 21:02:24	1.6
+++ cluster/fence/man/fenced.8	2007/08/17 18:26:16	1.7
@@ -170,10 +170,10 @@
 will need to manually reset the failed node and then use fence_ack_manual
 to tell fenced to continue on without fencing it (see override above).
 
-There is typically a single method used to fence each node, where the
-method refers to a specific device listed in the separate <fencedevices>
-section and then lists any node-specific parameters related to using the
-device.
+There is typically a single method used to fence each node (the name given
+to the method is not significant).  A method refers to a specific device
+listed in the separate <fencedevices> section, and then lists any
+node-specific parameters related to using the device.
 
   <clusternodes>
 
@@ -206,10 +206,57 @@
           <fencedevice name="myswitch" ipaddr="1.2.3.4" .../>
   </fencedevices>
 
+.SS Multiple methods for a node
+
+In more advanced configurations, multiple fencing methods can be defined
+for a node.  If fencing fails using the first method, fenced will try the
+next method, and continue to cycle through methods until one succeeds.
+
+  <clusternode name="node1" nodeid="1">
+          <fence>
+             <method name="first">
+                <device name="powerswitch" hw-specific-param="x"/>
+             </method>
+
+             <method name="second">
+                <device name="storageswitch" hw-specific-param="1"/>
+             </method>
+          </fence>
+  </clusternode>
+
+.SS Dual path, redundant power
+
+Sometimes fencing a node requires disabling two power ports or two i/o
+paths.  This is done by specifying two or more devices within a method.
+
+  <clusternode name="node1" nodeid="1">
+          <fence>
+             <method name="single">
+                <device name="sanswitch1" hw-specific-param="x"/>
+                <device name="sanswitch2" hw-specific-param="x"/>
+             </method>
+          </fence>
+  </clusternode>
+
+When using power switches to fence nodes with dual power supplies, the
+agents must be told to turn off both power ports before restoring power to
+either port.  The default off-on behavior of the agent could result in the
+power never being fully disabled to the node.
+
+  <clusternode name="node1" nodeid="1">
+          <fence>
+             <method name="single">
+                <device name="nps1" hw-param="x" action="off"/>
+                <device name="nps2" hw-param="x" action="off"/>
+                <device name="nps1" hw-param="x" action="on"/>
+                <device name="nps2" hw-param="x" action="on"/>
+             </method>
+          </fence>
+  </clusternode>
+
 .SS Hardware-specific settings
 
-Find documentation for configuring specific devices, multiple methods per
-node, and redundant-power/dual-path hardware at
+Find documentation for configuring specific devices at
 .BR
 http://sources.redhat.com/cluster/