* [Cluster-devel] cluster/fence/man fenced.8
@ 2007-08-16 21:02 teigland
0 siblings, 0 replies; 2+ messages in thread
From: teigland @ 2007-08-16 21:02 UTC (permalink / raw)
To: cluster-devel.redhat.com
CVSROOT: /cvs/cluster
Module name: cluster
Changes by: teigland at sourceware.org 2007-08-16 21:02:24
Modified files:
fence/man : fenced.8
Log message:
mention fencing override, describe the structure of node fencing
parameters in cluster.conf, point to web site for device-specific
documentation
Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/cluster/fence/man/fenced.8.diff?cvsroot=cluster&r1=1.5&r2=1.6
--- cluster/fence/man/fenced.8 2007/08/15 21:09:01 1.5
+++ cluster/fence/man/fenced.8 2007/08/16 21:02:24 1.6
@@ -108,6 +108,13 @@
are fenced by power cycling. If nodes are fenced by disabling their SAN
access, then unnecessarily fencing a node is usually less disruptive.
+.SS Fencing override
+
+If a fencing device fails, the agent may repeatedly return errors as
+fenced tries to fence a failed node. In this case, the admin can manually
+reset the failed node, and then use fence_ack_manual to tell fenced to
+continue without fencing the node.
+
.SH CONFIGURATION FILE
Fencing daemon behavior can be controlled by setting options in the
cluster.conf file under the section <fence_daemon> </fence_daemon>. See
@@ -118,27 +125,93 @@
Post-join delay is the number of seconds the daemon will wait before
fencing any victims after a node joins the domain.
- <fence_daemon post_join_delay="6">
- </fence_daemon>
+ <fence_daemon post_join_delay="6"/>
Post-fail delay is the number of seconds the daemon will wait before
fencing any victims after a domain member fails.
- <fence_daemon post_fail_delay="0">
- </fence_daemon>
+ <fence_daemon post_fail_delay="0"/>
Clean-start is used to prevent any startup fencing the daemon might do.
It indicates that the daemon should assume all nodes are in a clean state
to start.
- <fence_daemon clean_start="0">
- </fence_daemon>
+ <fence_daemon clean_start="0"/>
Override-path is the location of a FIFO used for communication between
fenced and fence_ack_manual.
- <fence_daemon override_path="/var/run/cluster/fenced_override">
- </fence_daemon>
+ <fence_daemon override_path="/var/run/cluster/fenced_override"/>
+
+.SS Per-node fencing settings
+
+The per-node fencing configuration can become complex and is largely
+specific to the hardware being used. The general framework begins like
+this:
+
+ <clusternodes>
+
+ <clusternode name="node1" nodeid="1">
+ <fence>
+ </fence>
+ </clusternode>
+
+ <clusternode name="node2" nodeid="2">
+ <fence>
+ </fence>
+ </clusternode>
+
+ ...
+ </clusternodes>
+
+The simple fragment above is a valid configuration: there is no way to
+fence these nodes. If one of these nodes is in the fence domain and
+fails, fenced will repeatedly fail in its attempts to fence it. The admin
+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.
+
+ <clusternodes>
+
+ <clusternode name="node1" nodeid="1">
+ <fence>
+ <method name="single">
+ <device name="myswitch" hw-specific-param="x"/>
+ </method>
+ </fence>
+ </clusternode>
+
+ <clusternode name="node2" nodeid="2">
+ <fence>
+ <method name="single">
+ <device name="myswitch" hw-specific-param="y"/>
+ </method>
+ </fence>
+ </clusternode>
+
+ ...
+ </clusternodes>
+
+.SS Fence device settings
+
+This section defines properties of the devices used to fence nodes. There
+may be one or more devices listed. The per-node fencing sections above
+reference one of these fence devices by name.
+
+ <fencedevices>
+ <fencedevice name="myswitch" ipaddr="1.2.3.4" .../>
+ </fencedevices>
+
+.SS Hardware-specific settings
+
+Find documentation for configuring specific devices, multiple methods per
+node, and redundant-power/dual-path hardware at
+.BR
+http://sources.redhat.com/cluster/
.SH OPTIONS
Command line options override corresonding values in cluster.conf.
^ permalink raw reply [flat|nested] 2+ messages in thread
* [Cluster-devel] cluster/fence/man fenced.8
@ 2007-08-17 18:26 teigland
0 siblings, 0 replies; 2+ messages in thread
From: teigland @ 2007-08-17 18:26 UTC (permalink / raw)
To: cluster-devel.redhat.com
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/
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