Synnefo » snf-ganeti

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  <!ENTITY dhdate      "<date>December 12, 2007</date>">

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  <!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>

      <holder>Google Inc.</holder>

    </copyright>

    &dhdate;

  </refentryinfo>

  <refmeta>

    &dhucpackage;

    &dhsection;

    <refmiscinfo>ganeti 1.2</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 (it's smarter 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>

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

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

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

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

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

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

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

        <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. Also it is advisable to reserve a per-cluster

        unique name, and not try to reuse one of the nodes' names.

      </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>-t</option> allows to set the hypervisor type of

        the cluster. Available hypervisor types are: xen-3.0, fake and

        xen-hvm3.1. The default is the xen-3.0 hypervisor.

        Note that if you init the cluster with hypervisor-type

        xen-hvm3.1 you also need to provide the cluster VNC password

        file <filename>/etc/ganeti/vnc-cluster-password</filename> and

        the HVM boot ISO image

        <filename>/srv/ganeti/iso/hvm-install.iso</filename> because

        instances created by the experimental HVM support require them.

      </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>

    </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>

      </cmdsynopsis>

      <para>

        Failover the master role to the current node.

      </para>

    </refsect2>

    <refsect2>

      <title>MODIFY</title>

      <cmdsynopsis>

        <command>modify</command>

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

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

      </cmdsynopsis>

        <para>

          Modify the options for the cluster.

        </para>

        <para>

          The <option>-g</option> and <option>--no-lvm-stoarge</option> are

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