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  <!ENTITY dhdate      "<date>February 12, 2009</date>">

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       allowed: see man(7), man(1). -->

  <!ENTITY dhsection   "<manvolnum>8</manvolnum>">

  <!ENTITY dhucpackage "<refentrytitle>gnt-cluster</refentrytitle>">

  <!ENTITY dhpackage   "gnt-cluster">

  <!ENTITY debian      "<productname>Debian</productname>">

  <!ENTITY gnu         "<acronym>GNU</acronym>">

  <!ENTITY gpl         "&gnu; <acronym>GPL</acronym>">

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<refentry>

  <refentryinfo>

    <copyright>

      <year>2006</year>

      <year>2007</year>

      <year>2008</year>

      <year>2009</year>

      <holder>Google Inc.</holder>

    </copyright>

    &dhdate;

  </refentryinfo>

  <refmeta>

    &dhucpackage;

    &dhsection;

    <refmiscinfo>ganeti 2.0</refmiscinfo>

  </refmeta>

  <refnamediv>

    <refname>&dhpackage;</refname>

    <refpurpose>ganeti administration, cluster-wide</refpurpose>

  </refnamediv>

  <refsynopsisdiv>

    <cmdsynopsis>

      <command>&dhpackage; </command>

      <arg choice="req">command</arg>

      <arg>arguments...</arg>

    </cmdsynopsis>

  </refsynopsisdiv>

  <refsect1>

    <title>DESCRIPTION</title>

    <para>

      The <command>&dhpackage;</command> is used for cluster-wide

      administration in the ganeti system.

    </para>

  </refsect1>

  <refsect1>

    <title>COMMANDS</title>

    <refsect2>

      <title>ADD-TAGS</title>

      <cmdsynopsis>

        <command>add-tags</command>

        <arg choice="opt">--from <replaceable>file</replaceable></arg>

        <arg choice="req"

        rep="repeat"><replaceable>tag</replaceable></arg>

      </cmdsynopsis>

      <para>

        Add tags to the cluster. If any of the tags contains invalid

        characters, the entire operation will abort.

      </para>

      <para>

        If the <option>--from</option> option is given, the list of

        tags will be extended with the contents of that file (each

        line becomes a tag). In this case, there is not need to pass

        tags on the command line (if you do, both sources will be

        used). A file name of - will be interpreted as stdin.

      </para>

    </refsect2>

    <refsect2>

      <title>COMMAND</title>

      <cmdsynopsis>

        <command>command</command>

        <arg>-n <replaceable>node</replaceable></arg>

        <arg choice="req"><replaceable>command</replaceable></arg>

      </cmdsynopsis>

      <para>

        Executes a command on all nodes. If the option

        <option>-n</option> is not given, the command will be executed

        on all nodes, otherwise it will be executed only on the

        node(s) specified. Use the option multiple times for running

        it on multiple nodes, like:

        <screen>

          # gnt-cluster command -n node1.example.com -n node2.example.com date

        </screen>

      </para>

      <para>

        The command is executed serially on the selected nodes. If the

        master node is present in the list, the command will be

        executed last on the master. Regarding the other nodes, the

        execution order is somewhat alphabetic, so that

        node2.example.com will be earlier than node10.example.com but

        after node1.example.com.

      </para>

      <para>

        So given the node names node1, node2, node3, node10, node11,

        with node3 being the master, the order will be: node1, node2,

        node10, node11, node3.

      </para>

      <para>

        The command is constructed by concatenating all other command

        line arguments. For example, to list the contents of the

        <filename class="directory">/etc</filename> directory on all

        nodes, run:

        <screen>

          # gnt-cluster command ls -l /etc

        </screen>

        and the command which will be executed will be

        <computeroutput>"ls -l /etc"</computeroutput>

      </para>

    </refsect2>

    <refsect2>

      <title>COPYFILE</title>

      <cmdsynopsis>

        <command>copyfile</command>

        <arg>-n <replaceable>node</replaceable></arg>

        <arg choice="req"><replaceable>file</replaceable></arg>

      </cmdsynopsis>

      <para>

        Copies a file to all or to some nodes. The argument specifies

        the source file (on the current system), the

        <option>-n</option> argument specifies the target node, or

        nodes if the option is given multiple times. If

        <option>-n</option> is not given at all, the file will be

        copied to all nodes.

        Example:

        <screen>

          # gnt-cluster -n node1.example.com -n node2.example.com copyfile /tmp/test

        </screen>

        This will copy the file <filename>/tmp/test</filename> from

        the current node to the two named nodes.

      </para>

    </refsect2>

    <refsect2>

      <title>DESTROY</title>

      <cmdsynopsis>

        <command>destroy</command>

        <arg choice="req">--yes-do-it</arg>

      </cmdsynopsis>

      <para>

        Remove all configuration files related to the cluster, so that

        a <command>gnt-cluster init</command> can be done again

        afterwards.

      </para>

      <para>

        Since this is a dangerous command, you are required to pass

        the argument <replaceable>--yes-do-it.</replaceable>

      </para>

    </refsect2>

    <refsect2>

      <title>GETMASTER</title>

      <cmdsynopsis>

        <command>getmaster</command>

      </cmdsynopsis>

      <para>

        Displays the current master node.

      </para>

    </refsect2>

    <refsect2>

      <title>INFO</title>

      <cmdsynopsis>

        <command>info</command>

      </cmdsynopsis>

      <para>

        Shows runtime cluster information: cluster name, architecture

        (32 or 64 bit), master node, node list and instance list.

      </para>

    </refsect2>

    <refsect2>

      <title>INIT</title>

      <cmdsynopsis>

        <command>init</command>

        <sbr>

        <arg>-s <replaceable>secondary_ip</replaceable></arg>

        <sbr>

        <arg>-b <replaceable>bridge</replaceable></arg>

        <sbr>

        <arg>-g <replaceable>vg-name</replaceable></arg>

        <sbr>

        <arg>--master-netdev <replaceable>vg-name</replaceable></arg>

        <sbr>

        <arg>-m <replaceable>mac-prefix</replaceable></arg>

        <sbr>

        <arg>--no-lvm-storage</arg>

        <sbr>

        <arg>--file-storage-dir <replaceable>dir</replaceable></arg>

        <sbr>

        <arg>--enabled-hypervisors <replaceable>hypervisors</replaceable></arg>

        <sbr>

        <arg>-t <replaceable>hypervisor name</replaceable></arg>

        <sbr>

        <arg>--hypervisor-parameters <replaceable>hypervisor</replaceable>:<replaceable>hv-param</replaceable>=<replaceable>value</replaceable><arg rep="repeat" choice="opt">,<replaceable>hv-param</replaceable>=<replaceable>value</replaceable></arg></arg>

        <sbr>

        <arg>--backend-parameters <replaceable>be-param</replaceable>=<replaceable>value</replaceable><arg rep="repeat" choice="opt">,<replaceable>be-param</replaceable>=<replaceable>value</replaceable></arg></arg>

        <sbr>

        <arg choice="req"><replaceable>clustername</replaceable></arg>

      </cmdsynopsis>

      <para>

        This commands is only run once initially on the first node of

        the cluster. It will initialize the cluster configuration and

        setup ssh-keys and more.

      </para>

      <para>

        Note that the <replaceable>clustername</replaceable> is not

        any random name. It has to be resolvable to an IP address

        using DNS, and it is best if you give the fully-qualified

        domain name. This hostname must resolve to an IP address

        reserved exclusively for this purpose.

      </para>

      <para>

        The cluster can run in two modes: single-home or

        dual-homed. In the first case, all traffic (both public

        traffic, inter-node traffic and data replication traffic) goes

        over the same interface. In the dual-homed case, the data

        replication traffic goes over the second network. The

        <option>-s</option> option here marks the cluster as

        dual-homed and its parameter represents this node's address on

        the second network. If you initialise the cluster with

        <option>-s</option>, all nodes added must have a secondary IP

        as well.

      </para>

      <para>

        Note that for Ganeti it doesn't matter if the secondary

        network is actually a separate physical network, or is done

        using tunneling, etc. For performance reasons, it's

        recommended to use a separate network, of course.

      </para>

      <para>

        The <option>-b</option> option specifies the default bridge

        for instances.

      </para>

      <para>

        The <option>-g</option> option will let you specify a volume group

        different than 'xenvg' for ganeti to use when creating instance disks.

        This volume group must have the same name on all nodes. Once the

        cluster is initialized this can be altered by using the

        <command>modify</command> command. If you don't want to use lvm

        storage at all use the <option>--no-lvm-storage</option> option.

        Once the cluster is initialized you can change this setup with the

        <command>modify</command> command.

      </para>

      <para>

        The <option>--master-netdev</option> option is useful for specifying a

        different interface on which the master will activate its IP address.

        It's important that all nodes have this interface because you'll need

        it for a master failover.

      </para>

      <para>

        The <option>-m</option> option will let you specify a three byte prefix

        under which the virtual MAC addresses of your instances will be

        generated. The prefix must be specified in the format XX:XX:XX and the

        default is aa:00:00.

      </para>

      <para>

        The <option>--no-lvm-storage</option> allows you to initialize the

        cluster without lvm support. This means that only instances using

        files as storage backend will be possible to create. Once the cluster

        is initialized you can change this setup with the

        <command>modify</command> command.

      </para>

      <para>

        The <option>--file-storage-dir</option> option allows you

        set the directory to use for storing the instance disk

        files when using file storage as backend for instance disks.

      </para>

      <para>

        The <option>--enabled-hypervisors</option> option allows you

        to set the list of hypervisors that will be enabled for

        this cluster. Instance hypervisors can only be choosen from

        the list of enabled hypervisors. Currently, the following

        hypervisors are available:

      </para>

      <para>

        <variablelist>

          <varlistentry>

            <term>xen-pvm</term>

            <listitem>

              <para>

                Xen PVM hypervisor

              </para>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>xen-hvm</term>

            <listitem>

              <para>

                Xen HVM hypervisor

              </para>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>kvm</term>

            <listitem>

              <para>

                Linux KVM hypervisor

              </para>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>fake</term>

            <listitem>

              <para>

                fake hypervisor for development/testing

              </para>

            </listitem>

          </varlistentry>

        </variablelist>

      </para>

      <para>

        Either a single hypervisor name or a comma-separated list of

        hypervisor names can be specified. If this option is not

        specified, only the xen-pvm hypervisor is enabled by default.

      </para>

      <para>

        With the <option>-t</option> option, the default hypervisor

        can be set. It has to be a member of the list of enabled

        hypervisors. If not specified, the first entry on the list of

        enabled hypervisors will be used by default.

      </para>

      <para>

        The <option>--backend-parameters</option> option allows you to set

        the default backend parameters for the cluster. The parameter

        format is a comma-separated list of key=value pairs with the

        following supported keys:

      </para>

      <para>

        <variablelist>

          <varlistentry>

            <term>vcpus</term>

            <listitem>

              <para>

                Number of VCPUs to set for an instance by default, must

                be an integer, will be set to 1 if no specified.

              </para>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>memory</term>

            <listitem>

              <para>

                Amount of memory to allocate for an instance by default,

                can be either an integer or an integer followed by a

                unit (M for mebibytes and G for gibibytes are

                supported), will be set to 128M if not specified.

              </para>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>auto_balance</term>

            <listitem>

              <para>

                Value of the auto_balance flag for instances to use by

                default, will be set to true if not specified.

              </para>

            </listitem>

          </varlistentry>

        </variablelist>

      </para>

      <para>

        The <option>--hypervisor-parameters</option> option allows you

        to set default hypervisor specific parameters for the

        cluster. The format of this option is the name of the

        hypervisor, followed by a colon and a comma-separated list of

        key=value pairs. The keys available for each hypervisors are

        detailed int the <citerefentry>

        <refentrytitle>gnt-instance</refentrytitle>

        <manvolnum>8</manvolnum> </citerefentry> man page, in the

        <command>add</command> command.

      </para>

    </refsect2>

    <refsect2>

      <title>LIST-TAGS</title>

      <cmdsynopsis>

        <command>list-tags</command>

      </cmdsynopsis>

      <para>List the tags of the cluster.</para>

    </refsect2>

    <refsect2>

      <title>MASTERFAILOVER</title>

      <cmdsynopsis>

        <command>masterfailover</command>

        <arg>--no-voting</arg>

      </cmdsynopsis>

      <para>

        Failover the master role to the current node.

      </para>

      <para>

        The <option>--no-voting</option> option skips the remote node agreement

        checks. This is dangerous, but necessary in some cases (for example

        failing over the master role in a 2 node cluster with the original master

        down). If the original master then comes up, it won't be able to start

        its master daemon because it won't have enough votes, but so won't the

        new master, if the master daemon ever needs a restart. You can pass

        --no-voting to ganeti-masterd on the new master to solve this problem,

        and gnt-cluster redist-conf to make sure the cluster is consistent again.

      </para>

    </refsect2>

    <refsect2>

      <title>MODIFY</title>

      <cmdsynopsis>

        <command>modify</command>

        <sbr>

        <arg choice="opt">-g <replaceable>vg-name</replaceable></arg>

        <sbr>

        <arg choice="opt">--no-lvm-storage</arg>

        <sbr>

        <arg choice="opt">--enabled-hypervisors

        <replaceable>hypervisors</replaceable></arg>

        <sbr>

        <arg choice="opt">--hypervisor-parameters <replaceable>hypervisor</replaceable>:<replaceable>hv-param</replaceable>=<replaceable>value</replaceable><arg rep="repeat" choice="opt">,<replaceable>hv-param</replaceable>=<replaceable>value</replaceable></arg></arg>

        <sbr>

        <arg choice="opt">--backend-parameters <replaceable>be-param</replaceable>=<replaceable>value</replaceable><arg rep="repeat" choice="opt">,<replaceable>be-param</replaceable>=<replaceable>value</replaceable></arg></arg>

        <sbr>

        <arg>-C <replaceable>candidate_pool_size</replaceable></arg>

      </cmdsynopsis>

        <para>

          Modify the options for the cluster.

        </para>

        <para>

          The <option>-g</option>, <option>--no-lvm-storarge</option>,

          <option>--enabled-hypervisors</option>,

          <option>--hypervisor-parameters</option> and

          <option>--backend-parameters</option> options are

          described in the <command>init</command> command.

        </para>

      <para>

        The <option>-C</option> options specifies the

        <varname>candidate_pool_size</varname> cluster parameter. This

        is the number of nodes that the master will try to keep as

        <literal>master_candidates</literal>. For more details about

        this role and other node roles, see the <citerefentry>

        <refentrytitle>ganeti</refentrytitle><manvolnum>7</manvolnum>

        </citerefentry>. If you increase the size, the master will

        automatically promote as many nodes as required and possible

        to reach the intended number.

      </para>

    </refsect2>

    <refsect2>

      <title>QUEUE</title>

      <cmdsynopsis>

        <command>queue</command>

        <arg choice="opt">drain</arg>

        <arg choice="opt">undrain</arg>

        <arg choice="opt">info</arg>

      </cmdsynopsis>

      <para>

        Change job queue properties.

      </para>

      <para>

        The <option>drain</option> option sets the drain flag on the

        job queue. No new jobs will be accepted, but jobs already in

        the queue will be processed.

      </para>

      <para>

        The <option>undrain</option> will unset the drain flag on the

        job queue. New jobs will be accepted.

      </para>

      <para>

        The <option>info</option> option shows the properties of the

        job queue.

      </para>

    </refsect2>

    <refsect2>

      <title>redist-conf</title>

      <cmdsynopsis>

        <command>redist-conf</command>

          <arg>--submit</arg>

      </cmdsynopsis>

      <para>

        This command forces a full push of configuration files from

        the master node to the other nodes in the cluster. This is

        normally not needed, but can be run if the

        <command>verify</command> complains about configuration

        mismatches.

      </para>

      <para>

        The <option>--submit</option> option is used to send the job

        to the master daemon but not wait for its completion. The job

        ID will be shown so that it can be examined via

        <command>gnt-job info</command>.

      </para>

    </refsect2>

    <refsect2>

      <title>REMOVE-TAGS</title>

      <cmdsynopsis>

        <command>remove-tags</command>

        <arg choice="opt">--from <replaceable>file</replaceable></arg>

        <arg choice="req"

        rep="repeat"><replaceable>tag</replaceable></arg>

      </cmdsynopsis>

      <para>

        Remove tags from the cluster. If any of the tags are not

        existing on the cluster, the entire operation will abort.

      </para>

      <para>

        If the <option>--from</option> option is given, the list of

        tags will be extended with the contents of that file (each

        line becomes a tag). In this case, there is not need to pass

        tags on the command line (if you do, both sources will be

        used). A file name of - will be interpreted as stdin.

      </para>

    </refsect2>

    <refsect2>

      <title>RENAME</title>

      <cmdsynopsis>

        <command>rename</command>

        <arg>-f</arg>

        <arg choice="req"><replaceable>name</replaceable></arg>

      </cmdsynopsis>

      <para>

        Renames the cluster and in the process updates the master IP

        address to the one the new name resolves to. At least one of

        either the name or the IP address must be different, otherwise

        the operation will be aborted.

      </para>

      <para>

        Note that since this command can be dangerous (especially when

        run over SSH), the command will require confirmation unless

        run with the <option>-f</option> option.

      </para>

    </refsect2>

    <refsect2>

      <title>REPAIR-DISK-SIZES</title>

      <cmdsynopsis>

        <command>repair-disk-sizes</command>

        <arg rep="repeat">instance</arg>

      </cmdsynopsis>

      <para>

        This command checks that the recorded size of the given

        instance's disks matches the actual size and updates any

        mismatches found. This is needed if the Ganeti configuration

        is no longer consistent with reality, as it will impact some

        disk operations. If no arguments are given, all instances will

        be checked.

      </para>

      <para>

        Note that only active disks can be checked by this command; in

        case a disk cannot be activated it's advised to use

        <command>gnt-instance activate-disks --ignore-size

        ...</command> to force activation without regard to the

        current size.

      </para>

      <para>

        When the all disk sizes are consistent, the command will

        return no output. Otherwise it will log details about the

        inconsistencies in the configuration.

      </para>

    </refsect2>

    <refsect2>

      <title>SEARCH-TAGS</title>

      <cmdsynopsis>

        <command>search-tags</command>

        <arg choice="req"><replaceable>pattern</replaceable></arg>

      </cmdsynopsis>

      <para>

        Searches the tags on all objects in the cluster (the cluster

        itself, the nodes and the instances) for a given pattern. The

        pattern is interpreted as a regular expression and a search

        will be done on it (i.e. the given pattern is not anchored to

        the beggining of the string; if you want that, prefix the

        pattern with <literal>^</literal>).

      </para>

      <para>

        If no tags are matching the pattern, the exit code of the

        command will be one. If there is at least one match, the exit

        code will be zero. Each match is listed on one line, the

        object and the tag separated by a space. The cluster will be

        listed as <filename>/cluster</filename>, a node will be listed

        as

        <filename>/nodes/<replaceable>name</replaceable></filename>,

        and an instance as

        <filename>/instances/<replaceable>name</replaceable></filename>.

        Example:

      </para>

<screen>

# gnt-cluster search-tags time

/cluster ctime:2007-09-01

/nodes/node1.example.com mtime:2007-10-04

</screen>

    </refsect2>

    <refsect2>

      <title>VERIFY</title>

      <cmdsynopsis>

        <command>verify</command>

        <arg choice="opt">--no-nplus1-mem</arg>

      </cmdsynopsis>

      <para>

        Verify correctness of cluster configuration. This is safe with

        respect to running instances, and incurs no downtime of the

        instances.

      </para>

      <para>

        If the <option>--no-nplus1-mem</option> option is given, ganeti won't

        check whether if it loses a node it can restart all the instances on

        their secondaries (and report an error otherwise).

      </para>

    </refsect2>

    <refsect2>

      <title>VERIFY-DISKS</title>

      <cmdsynopsis>

        <command>verify-disks</command>

      </cmdsynopsis>

      <para>

        The command checks which instances have degraded DRBD disks

        and activates the disks of those instances.

      </para>

      <para>

        This command is run from the <command>ganeti-watcher</command>

        tool, which also has a different, complementary algorithm for

        doing this check. Together, these two should ensure that DRBD

        disks are kept consistent.

      </para>

    </refsect2>

    <refsect2>

      <title>VERSION</title>

      <cmdsynopsis>

        <command>version</command>

      </cmdsynopsis>

      <para>

        Show the cluster version.

      </para>

    </refsect2>

  </refsect1>

  &footer;

</refentry>

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