cman(5) - f7

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3cman(5)                                                   cman(5)
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NAME

6       cman ‐ cluster.conf cman configuration section
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DESCRIPTION

11       Cman configuration values are placed in the <cman> </cman>
12       section of cluster.conf.  Per‐node  configuration  related
13       to  cman  is  placed in the standard <clusternode> </clus‐
14       ternode> sections.  All cman  configuration  settings  are
15       optional; usually none are used.
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UDP port

19       By default, cman will use UDP port 6809 for internode com‐
20       munication.  This can be changed by setting a port  number
21       as follows:
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23         <cman port="6809">
24         </cman>
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Expected votes

28       The expected votes value is used by cman to determine quo‐
29       rum.  The cluster is quorate if the sum of votes of exist‐
30       ing  members is over half of the expected votes value.  By
31       default, cman_tool sets the expected votes value to be the
32       sum  of  votes  of all nodes listed in cluster.conf.  This
33       can be overriden by  setting  an  explicit  expected_votes
34       value as follows:
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36         <cman expected_votes="3">
37         </cman>
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39       If  the  cluster becomes partitioned, improper use of this
40       option can result in more than one partition gaining  quo‐
41       rum.   In  that event, nodes in each partition will enable
42       cluster services.
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Two node clusters

46       Ordinarily, the loss of quorum after one out of two  nodes
47       fails  will prevent the remaining node from continuing (if
48       both nodes have one vote.)  Special configuration  options
49       can be set to allow the one remaining node to continue op‐
50       erating if the other fails.  To do this  only  two  nodes,
51       each  with  one vote, can be defined in cluster.conf.  The
52       two_node and expected_votes values must then be set  to  1
53       in the cman section as follows.
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55         <cman two_node="1" expected_votes="1">
56         </cman>
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Node votes

60       By  default,  a node is given one vote toward the calcula‐
61       tion of quorum.  This can be changed by giving  a  node  a
62       specific number of votes as follows:
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64         <clusternode name="nd1" votes="2">
65         </clusternode>
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Node ID

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70       By  default,  a  node  is assigned a nodeid by the cluster
71       manager (cman) when it joins the  cluster.   This  can  be
72       overriden  by specifying a nodeid here.  Using this option
73       will ensure that a given node always has the same  ID.   A
74       node’s  application to join the cluster may be rejected if
75       you try to set the nodeid to one that is already used.
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77         <clusternode name="nd1" nodeid="1">
78         </clusternode>
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Multicast network configuration

82       Cman can be configured to use multicast instead of  broad‐
83       cast (broadcast is used by default if no multicast parame‐
84       ters are given.)  To configure multicast add one line  un‐
85       der the <cman> section and another under the <clusternode>
86       section:
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88         <cman>
89             <multicast addr="224.0.0.1"/>
90         </cman>
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92         <clusternode name="nd1">
93             <multicast addr="224.0.0.1" interface="eth0"/>
94         </clusternode>
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96       The multicast addresses must match and the address must be
97       usable on the interface name given for the node.
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