samba-mirror/ctdb/doc/onnode.1.xml

<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE refentry PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
<refentry id="onnode.1">

<refmeta>
	<refentrytitle>onnode</refentrytitle>
	<manvolnum>1</manvolnum>
</refmeta>


<refnamediv>
	<refname>onnode</refname>
        <refpurpose>run commands on ctdb nodes</refpurpose>
</refnamediv>

<refsynopsisdiv>
	<cmdsynopsis>
		<command>onnode [OPTION] ... NODES COMMAND ...</command>
	</cmdsynopsis>
</refsynopsisdiv>

  <refsect1><title>DESCRIPTION</title>
    <para>
      onnode is a utility to run commands on a specific node of a CTDB
      cluster, or on all nodes.
    </para>
    <para>
      The NODES option specifies which node to run a command on. You
      can specify a numeric node number (from 0 to N-1) or the special
      node 'all'.  You can also specify lists of nodes, separated by
      commas, and ranges of numeric node numbers, separated by dashes.
      If nodes are specified multiple times then the command will be
      executed multiple times on those nodes.  The order of nodes is
      significant.
    </para>
    <para>
      The COMMAND can be any shell command. The onnode utility uses
      ssh or rsh to connect to the remote nodes and run the command.
      </para>
  </refsect1>

  <refsect1><title>OPTIONS</title>

    <variablelist>
      <varlistentry><term>-c</term>
        <listitem>
          <para>
            Execute COMMAND in the current working directory on each
            node.
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry><term>-p</term>
        <listitem>
          <para>
            Run commands in parallel on the specified nodes.  In this
            mode 
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry><term>-q</term>
        <listitem>
          <para>
            Do not print node addresses.  Normally, onnode prints
            informational node addresses if more than one node is
            specified.  This overrides -v.
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry><term>-v</term>
        <listitem>
          <para>
            Print a node addresses even if only one node is specified.
            Normally, onnode prints informational node addresses when
            more than one node is specified.
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry><term>-h, --help</term>
        <listitem>
          <para>
            Show a short usage guide.
	  </para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1><title>EXAMPLES</title>
    <para>
      The following command would show the process ID of ctdb on all nodes
    </para>
    <screen format="linespecific">
      onnode all pidof ctdbd
    </screen>

    <para>
      The following command would show the last 5 lines of log on each
      node, preceded by the node's hostname
    </para>
    <screen format="linespecific">
      onnode all "hostname; tail -5 /var/log/log.ctdb"
    </screen>

    <para>
      The following command would restart the ctdb service on all nodes.
    </para>
    <screen format="linespecific">
      onnode all service ctdb restart
    </screen>

    <para>
      The following command would run ./foo in the current working
      directory, in parallel, on nodes 0, 2, 3 and 4.
    </para>
    <screen format="linespecific">
      onnode -c -p 0,2-4 ./foo
    </screen>
  </refsect1>

  <refsect1><title>FILES</title>

    <variablelist>
      <varlistentry><term>/etc/ctdb/nodes</term>
        <listitem>
          <para>
            Contains a list of each node's IP address or hostname.
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry><term>/etc/ctdb/onnode.conf</term>
        <listitem>
          <para>
            If this file exists it is sourced by onnode.  The main
            purpose is to allow the administrator to set $SSH to
            something other than "ssh".  In this case the -t option is
            ignored.  For example, the administrator may choose to use
            use rsh instead of ssh.
	  </para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1><title>SEE ALSO</title>
    <para>
      ctdbd(1), ctdb(1), <ulink url="http://ctdb.samba.org/"/>
    </para>
  </refsect1>
  <refsect1><title>COPYRIGHT/LICENSE</title>
<literallayout>
Copyright (C) Andrew Tridgell 2007
Copyright (C) Ronnie sahlberg 2007
Copyright (C) Martin Schwenke 2008

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or (at
your option) any later version.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, see http://www.gnu.org/licenses/.
</literallayout>
  </refsect1>
</refentry>