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<!doctype refentry PUBLIC "-//OASIS//DTD DocBook V4.1//EN" [

  <!-- Fill in your name for FIRSTNAME and SURNAME. -->

  <!-- Please adjust the date whenever revising the manpage. -->

  <!ENTITY dhdate      "<date>June 08, 2010</date>">

  <!-- SECTION should be 1-8, maybe w/ subsection other parameters are

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

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

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

  <!ENTITY dhpackage   "gnt-node">

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

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

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

  <!ENTITY footer SYSTEM "footer.sgml">

]>

<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 2.2</refmiscinfo>

  </refmeta>

  <refnamediv>

    <refname>&dhpackage;</refname>

    <refpurpose>Node administration</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 managing the

      (physical) nodes in the Ganeti system.

    </para>

  </refsect1>

  <refsect1>

    <title>COMMANDS</title>

    <refsect2>

      <title>ADD</title>

      <cmdsynopsis>

        <command>add</command>

        <arg>--readd</arg>

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

        <arg>-g <replaceable>nodegroup</replaceable></arg>

        <arg>--master-capable=<option>yes|no</option></arg>

        <arg>--vm-capable=<option>yes|no</option></arg>

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

      </cmdsynopsis>

      <para>

        Adds the given node to the cluster.

      </para>

      <para>

        This command is used to join a new node to the cluster. You

        will have to provide the password for root of the node to be

        able to add the node in the cluster. The command needs to be

        run on the Ganeti master.

      </para>

      <para>

        Note that the command is potentially destructive, as it will

        forcibly join the specified host the cluster, not paying

        attention to its current status (it could be already in a

        cluster, etc.)

      </para>

      <para>

        The <option>-s</option> is used in dual-home clusters and

        specifies the new node's IP in the secondary network. See the

        discussion in <citerefentry>

        <refentrytitle>gnt-cluster</refentrytitle>

        <manvolnum>8</manvolnum> </citerefentry> for more

        information.

      </para>

      <para>

        In case you're readding a node after hardware failure, you can

        use the <option>--readd</option> parameter. In this case, you

        don't need to pass the secondary IP again, it will reused from

        the cluster. Also, the <literal>drained</literal> and

        <literal>offline</literal> flags of the node will be cleared

        before re-adding it.

      </para>

      <para>

        The <option>-g</option> is used to add the new node into a specific

        node group, specified by uuid or name. If only one node group exists

        you can skip this option, otherwise it's mandatory.

      </para>

      <para>

        The <option>vm_capable</option>

        and <option>master_capable</option> options are described

        in <citerefentry><refentrytitle>ganeti</refentrytitle><manvolnum>7</manvolnum></citerefentry>,

        and are used to set the properties of the new node.

      </para>

      <para>

        Example:

        <screen>

# gnt-node add node5.example.com

# gnt-node add -s 192.0.2.5 node5.example.com

# gnt-node add -g group2 -s 192.0.2.9 node9.group2.example.com

        </screen>

      </para>

    </refsect2>

    <refsect2>

      <title>ADD-TAGS</title>

      <cmdsynopsis>

        <command>add-tags</command>

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

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

        <arg choice="req"

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

      </cmdsynopsis>

      <para>

        Add tags to the given node. 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>EVACUATE</title>

      <cmdsynopsis>

        <command>evacuate</command>

        <arg>-f</arg>

        <arg>--early-release</arg>

        <group>

          <arg>--iallocator <replaceable>NAME</replaceable></arg>

          <arg>--new-secondary <replaceable>destination_node</replaceable></arg>

        </group>

        <arg choice="req" rep="repeat"><replaceable>node</replaceable></arg>

      </cmdsynopsis>

      <para>

        This command will move all secondary instances away from the

        given node(s). It works only for instances having a drbd disk

        template.

      </para>

      <para>

        The new location for the instances can be specified in two ways:

        <itemizedlist>

          <listitem>

            <simpara>as a single node for all instances, via the

            <option>--new-secondary</option> option</simpara>

          </listitem>

          <listitem>

            <simpara>or via the <option>--iallocator</option> option,

            giving a script name as parameter, so each instance will

            be in turn placed on the (per the script) optimal

            node</simpara>

          </listitem>

        </itemizedlist>

      </para>

      <para>

        The <option>--early-release</option> changes the code so that

        the old storage on node being evacuated is removed early

        (before the resync is completed) and the internal Ganeti locks

        are also released for both the current secondary and the new

        secondary, thus allowing more parallelism in the cluster

        operation. This should be used only when recovering from a

        disk failure on the current secondary (thus the old storage is

        already broken) or when the storage on the primary node is

        known to be fine (thus we won't need the old storage for

        potential recovery).

      </para>

      <para>

        Example:

        <screen>

          # gnt-node evacuate -I dumb node3.example.com

        </screen>

      </para>

    </refsect2>

    <refsect2>

      <title>FAILOVER</title>

      <cmdsynopsis>

        <command>failover</command>

        <arg>-f</arg>

        <arg>--ignore-consistency</arg>

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

      </cmdsynopsis>

      <para>

        This command will fail over all instances having the given

        node as primary to their secondary nodes. This works only for

        instances having a drbd disk template.

      </para>

      <para>

        Normally the failover will check the consistency of the disks

        before failing over the instance. If you are trying to migrate

        instances off a dead node, this will fail. Use the

        <option>--ignore-consistency</option> option for this purpose.

      </para>

      <para>

        Example:

        <screen>

          # gnt-node failover node1.example.com

        </screen>

      </para>

    </refsect2>

    <refsect2>

      <title>INFO</title>

      <cmdsynopsis>

        <command>info</command>

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

      </cmdsynopsis>

      <para>

        Show detailed information about the nodes in the cluster. If you

        don't give any arguments, all nodes will be shows, otherwise the

        output will be restricted to the given names.

      </para>

    </refsect2>

    <refsect2>

      <title>LIST</title>

      <cmdsynopsis>

        <command>list</command>

        <arg>--sync</arg>

        <sbr>

        <arg>--no-headers</arg>

        <arg>--separator=<replaceable>SEPARATOR</replaceable></arg>

        <sbr>

        <arg>--units=<replaceable>UNITS</replaceable></arg>

        <arg>-o <replaceable>[+]FIELD,...</replaceable></arg>

        <sbr>

        <arg>--roman</arg>

        <sbr>

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

      </cmdsynopsis>

      <para>

        Lists the nodes in the cluster.

      </para>

      <para>

        The <option>--no-headers</option> option will skip the initial

        header line. The <option>--separator</option> option takes an

        argument which denotes what will be used between the output

        fields. Both these options are to help scripting.

      </para>

      <para>

        The units used to display the numeric values in the output

        varies, depending on the options given. By default, the values

        will be formatted in the most appropriate unit. If the

        <option>--separator</option> option is given, then the values

        are shown in mebibytes to allow parsing by scripts. In both

        cases, the <option>--units</option> option can be used to

        enforce a given output unit.

      </para>

      <para>

        By default, the query of nodes will be done in parallel with

        any running jobs. This might give inconsistent results for the

        free disk/memory. The <option>--sync</option> can be used to

        grab locks for all the nodes and ensure consistent view of the

        cluster (but this might stall the query for a long time).

      </para>

      <para>

        Passing the <option>--roman</option> option gnt-node list will try to

        output some of its fields in a latin-friendly way. This is not the

        default for backwards compatibility.

      </para>

      <para>

        The <option>-o</option> option takes a comma-separated list of

        output fields. The available fields and their meaning are:

        <variablelist>

          <varlistentry>

            <term>name</term>

            <listitem>

              <simpara>the node name</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>pinst_cnt</term>

            <listitem>

              <simpara>the number of instances having this node as

              primary</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>pinst_list</term>

            <listitem>

              <simpara>the list of instances having this node as

              primary, comma separated</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>sinst_cnt</term>

            <listitem>

              <simpara>the number of instances having this node as a

              secondary node</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>sinst_list</term>

            <listitem>

              <simpara>the list of instances having this node as a

              secondary node, comma separated</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>pip</term>

            <listitem>

              <simpara>the primary ip of this node (used for cluster

              communication)</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>sip</term>

            <listitem>

              <simpara>

                the secondary ip of this node (used for data

                replication in dual-ip clusters, see <citerefentry>

                <refentrytitle>gnt-cluster</refentrytitle>

                <manvolnum>8</manvolnum>

                </citerefentry>

              </simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>dtotal</term>

            <listitem>

              <simpara>total disk space in the volume group used for

              instance disk allocations</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>dfree</term>

            <listitem>

              <simpara>available disk space in the volume group</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>mtotal</term>

            <listitem>

              <simpara>total memory on the physical node</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>mnode</term>

            <listitem>

              <simpara>the memory used by the node itself</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>mfree</term>

            <listitem>

              <simpara>memory available for instance

              allocations</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>bootid</term>

            <listitem>

              <simpara>the node bootid value; this is a linux specific

              feature that assigns a new UUID to the node at each boot

              and can be use to detect node reboots (by tracking

              changes in this value)</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>tags</term>

            <listitem>

              <simpara>comma-separated list of the node's

              tags</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>serial_no</term>

            <listitem>

              <simpara>the so called 'serial number' of the node;

              this is a numeric field that is incremented each time

              the node is modified, and it can be used to detect

              modifications</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>ctime</term>

            <listitem>

              <para>

                the creation time of the node; note that this field

                contains spaces and as such it's harder to parse

              </para>

              <para>

                if this attribute is not present (e.g. when upgrading

                from older versions), then "N/A" will be shown instead

              </para>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>mtime</term>

            <listitem>

              <para>

                the last modification time of the node; note that this

                field contains spaces and as such it's harder to parse

              </para>

              <para>

                if this attribute is not present (e.g. when upgrading

                from older versions), then "N/A" will be shown instead

              </para>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>uuid</term>

            <listitem>

              <simpara>Show the UUID of the node (generated

                automatically by Ganeti)</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>ctotal</term>

            <listitem>

              <simpara>the toal number of logical processors</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>cnodes</term>

            <listitem>

              <simpara>the number of NUMA domains on the node, if the

              hypervisor can export this information</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>csockets</term>

            <listitem>

              <simpara>the number of physical CPU sockets, if the

              hypervisor can export this information</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>master_candidate</term>

            <listitem>

              <simpara>whether the node is a master candidate or not</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>drained</term>

            <listitem>

              <simpara>whether the node is drained or not; the cluster

              still communicates with drained nodes but excludes them

              from allocation operations</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>offline</term>

            <listitem>

              <simpara>whether the node is offline or not; if offline,

              the cluster does not communicate with offline nodes;

              useful for nodes that are not reachable in order to

              avoid delays</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>role</term>

            <listitem>

              <para>

                A condensed version of the node flags; this field will

                output a one-character field, with the following

                possible values:

                <itemizedlist>

                  <listitem>

                    <simpara><emphasis>M</emphasis> for the master

                    node</simpara>

                  </listitem>

                  <listitem>

                    <simpara><emphasis>C</emphasis> for a master

                    candidate</simpara>

                  </listitem>

                  <listitem>

                    <simpara><emphasis>R</emphasis> for a regular

                    node</simpara>

                  </listitem>

                  <listitem>

                    <simpara><emphasis>D</emphasis> for a drained

                    node</simpara>

                  </listitem>

                  <listitem>

                    <simpara><emphasis>O</emphasis> for an offline

                    node</simpara>

                  </listitem>

                </itemizedlist>

              </para>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>master_capable</term>

            <listitem>

              <para>whether the node can become a master candidate</para>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>vm_capable</term>

            <listitem>

              <para>whether the node can host instances</para>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>group</term>

            <listitem>

              <para>the name of the node's group, if known (the query

              is done without locking, so data consistency is not

              guaranteed)</para>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>group.uuid</term>

            <listitem>

              <para>the UUID of the node's group</para>

            </listitem>

          </varlistentry>

        </variablelist>

      </para>

      <para>

        If the value of the option starts with the character

        <constant>+</constant>, the new fields will be added to the

        default list. This allows to quickly see the default list plus

        a few other fields, instead of retyping the entire list of

        fields.

      </para>

      <para>

        Note that some of this fields are known from the configuration

        of the cluster (e.g. <simplelist type="inline">

        <member>name</member> <member>pinst</member>

        <member>sinst</member> <member>pip</member>

        <member>sip</member> </simplelist> and thus the master does

        not need to contact the node for this data (making the listing

        fast if only fields from this set are selected), whereas the

        other fields are "live" fields and we need to make a query to

        the cluster nodes.

      </para>

      <para>

        Depending on the virtualization type and implementation

        details, the mtotal, mnode and mfree may have slighly varying

        meanings. For example, some solutions share the node memory

        with the pool of memory used for instances

        (<acronym>KVM</acronym>), whereas others have separate memory

        for the node and for the instances (Xen).

      </para>

      <para>

        If no node names are given, then all nodes are

        queried. Otherwise, only the given nodes will be listed.

      </para>

    </refsect2>

    <refsect2>

      <title>LIST-TAGS</title>

      <cmdsynopsis>

        <command>list-tags</command>

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

      </cmdsynopsis>

      <para>List the tags of the given node.</para>

    </refsect2>

    <refsect2>

      <title>MIGRATE</title>

      <cmdsynopsis>

        <command>migrate</command>

        <arg>-f</arg>

        <arg>--non-live</arg>

        <arg>--migration-mode=live|non-live</arg>

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

      </cmdsynopsis>

      <para>

        This command will migrate all instances having the given

        node as primary to their secondary nodes. This works only for

        instances having a drbd disk template.

      </para>

      <para>

        As for the <command>gnt-instance migrate</command> command,

        the options <option>--no-live</option>

        and <option>--migration-mode</option> can be given to

        influence the migration type.

      </para>

      <para>

        Example:

        <screen>

          # gnt-node migrate node1.example.com

        </screen>

      </para>

    </refsect2>

    <refsect2>

      <title>MODIFY</title>

      <cmdsynopsis>

        <command>modify</command>

        <arg>-f</arg>

        <arg>--submit</arg>

        <arg>--master-candidate=<option>yes|no</option></arg>

        <arg>--drained=<option>yes|no</option></arg>

        <arg>--offline=<option>yes|no</option></arg>

        <arg>--master-capable=<option>yes|no</option></arg>

        <arg>--vm-capable=<option>yes|no</option></arg>

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

        <arg>--auto-promote</arg>

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

      </cmdsynopsis>

      <para>

        This command changes the role of the node. Each options takes

        either a literal <literal>yes</literal> or

        <literal>no</literal>, and only one option should be given as

        <literal>yes</literal>. The meaning of the roles and flags are

        described in the manpage <citerefentry>

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

        </citerefentry>.

      </para>

      <para>

        In case a node is demoted from the master candidate role, the

        operation will be refused unless you pass

        the <option>--auto-promote</option> option. This option will

        cause the operation to lock all cluster nodes (thus it will

        not be able to run in parallel with most other jobs), but it

        allows automated maintenance of the cluster candidate pool. If

        locking all cluster node is too expensive, another option is

        to promote manually another node to master candidate before

        demoting the current one.

      </para>

      <para>

        Example (setting a node offline, which will demote it from

        master candidate role if is in that role):

        <screen>

# gnt-node modify --offline=yes node1.example.com

        </screen>

      </para>

      <para>

        The <option>-s</option> can be used to change the node's secondary ip.

        No drbd instances can be running on the node, while this operation is

        taking place.

      </para>

      <para>Example (setting the node back to online and master candidate):

        <screen>

# gnt-node modify --offline=no --master-candidate=yes node1.example.com

        </screen>

      </para>

    </refsect2>

    <refsect2>

      <title>REMOVE</title>

      <cmdsynopsis>

        <command>remove</command>

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

      </cmdsynopsis>

      <para>

        Removes a node from the cluster. Instances must be removed or

        migrated to another cluster before.

      </para>

      <para>

        Example:

        <screen>

# gnt-node remove node5.example.com

        </screen>

      </para>

    </refsect2>

    <refsect2>

      <title>REMOVE-TAGS</title>

      <cmdsynopsis>

        <command>remove-tags</command>

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

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

        <arg choice="req"

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

      </cmdsynopsis>

      <para>

        Remove tags from the given node. If any of the tags are not

        existing on the node, 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>VOLUMES</title>

      <cmdsynopsis>

        <command>volumes</command>

        <arg>--no-headers</arg>

        <arg>--human-readable</arg>

        <arg>--separator=<replaceable>SEPARATOR</replaceable></arg>

        <arg>--output=<replaceable>FIELDS</replaceable></arg>

        <sbr>

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

      </cmdsynopsis>

      <para>

        Lists all logical volumes and their physical disks from the node(s)

        provided.

      </para>

      <para>

        The <option>--no-headers</option> option will skip the initial

        header line. The <option>--separator</option> option takes an

        argument which denotes what will be used between the output

        fields. Both these options are to help scripting.

      </para>

      <para>

        The units used to display the numeric values in the output

        varies, depending on the options given. By default, the values

        will be formatted in the most appropriate unit. If the

        <option>--separator</option> option is given, then the values

        are shown in mebibytes to allow parsing by scripts. In both

        cases, the <option>--units</option> option can be used to

        enforce a given output unit.

      </para>

      <para>

        The <option>-o</option> option takes a comma-separated list of

        output fields. The available fields and their meaning are:

        <variablelist>

          <varlistentry>

            <term>node</term>

            <listitem>

              <simpara>the node name on which the volume exists</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>phys</term>

            <listitem>

              <simpara>the physical drive (on which the LVM physical

              volume lives)</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>vg</term>

            <listitem>

              <simpara>the volume group name</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>name</term>

            <listitem>

              <simpara>the logical volume name</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>size</term>

            <listitem>

              <simpara>the logical volume size</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>instance</term>

            <listitem>

              <simpara>The name of the instance to which this volume

              belongs, or (in case it's an orphan volume) the

              character <quote>-</quote></simpara>

            </listitem>

          </varlistentry>

        </variablelist>

      </para>

      <para>

        Example:

        <screen>

# gnt-node volumes node5.example.com

Node              PhysDev   VG    Name                                 Size Instance

node1.example.com /dev/hdc1 xenvg instance1.example.com-sda_11000.meta 128  instance1.example.com

node1.example.com /dev/hdc1 xenvg instance1.example.com-sda_11001.data 256  instance1.example.com

        </screen>

      </para>

    </refsect2>

    <refsect2>

      <title>LIST-STORAGE</title>

      <cmdsynopsis>

        <command>list-storage</command>

        <arg>--no-headers</arg>

        <arg>--human-readable</arg>

        <arg>--separator=<replaceable>SEPARATOR</replaceable></arg>

        <arg>--storage-type=<replaceable>STORAGE_TYPE</replaceable></arg>

        <arg>--output=<replaceable>FIELDS</replaceable></arg>

        <sbr>

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

      </cmdsynopsis>

      <para>

        Lists the available storage units and their details for the

        given node(s).

      </para>

      <para>

        The <option>--no-headers</option> option will skip the initial header

        line. The <option>--separator</option> option takes an argument which

        denotes what will be used between the output fields. Both these options

        are to help scripting.

      </para>

      <para>

        The units used to display the numeric values in the output varies,

        depending on the options given. By default, the values will be

        formatted in the most appropriate unit. If the

        <option>--separator</option> option is given, then the values are shown

        in mebibytes to allow parsing by scripts. In both cases, the

        <option>--units</option> option can be used to enforce a given output

        unit.

      </para>

      <para>

        The <option>--storage-type</option> option can be used to choose a

        storage unit type. Possible choices are <literal>lvm-pv</literal>,

        <literal>lvm-vg</literal> or <literal>file</literal>.

      </para>

      <para>

        The <option>-o</option> option takes a comma-separated list of

        output fields. The available fields and their meaning are:

        <variablelist>

          <varlistentry>

            <term>node</term>

            <listitem>

              <simpara>the node name on which the volume exists</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>type</term>

            <listitem>

              <simpara>the type of the storage unit (currently just

              what is passed in via

              <option>--storage-type</option>)</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>name</term>

            <listitem>

              <simpara>the path/identifier of the storage unit</simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>size</term>

            <listitem>

              <simpara>

                total size of the unit; for the file type see a note below

              </simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>used</term>

            <listitem>

              <simpara>

                used space in the unit; for the file type see a note below

              </simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>free</term>

            <listitem>

              <simpara>

                available disk space

              </simpara>

            </listitem>

          </varlistentry>

          <varlistentry>

            <term>allocatable</term>

            <listitem>

              <simpara>

                whether we the unit is available for allocation

                (only <literal>lvm-pv</literal> can change this

                setting, the other types always report true)

              </simpara>

            </listitem>

          </varlistentry>

        </variablelist>

      </para>

      <para>

        Note that for the <quote>file</quote> type, the total disk

        space might not equal to the sum of used and free, due to the

        method Ganeti uses to compute each of them. The total and free

        values are computed as the total and free space values for the

        filesystem to which the directory belongs, but the used space

        is computed from the used space under that directory

        <emphasis>only</emphasis>, which might not be necessarily the

        root of the filesystem, and as such there could be files

        outside the file storage directory using disk space and

        causing a mismatch in the values.

      </para>

      <para>

        Example:

        <screen>

node1# gnt-node list-storage node2

Node  Type   Name        Size Used   Free Allocatable

node2 lvm-pv /dev/sda7 673.8G 1.5G 672.3G Y

node2 lvm-pv /dev/sdb1 698.6G   0M 698.6G Y

        </screen>

      </para>

    </refsect2>

    <refsect2>

      <title>MODIFY-STORAGE</title>

      <cmdsynopsis>

        <command>modify-storage</command>

        <arg><option>--allocatable=yes|no</option></arg>

        <sbr>

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

        <arg choice="req"><replaceable>storage-type</replaceable></arg>

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

      </cmdsynopsis>

      <para>

        Modifies storage volumes on a node. Only LVM physical volumes

        can be modified at the moment. They have a storage type

        of <quote>lvm-pv</quote>.

      </para>

      <para>

        Example:

        <screen>

# gnt-node modify-storage --allocatable no node5.example.com lvm-pv /dev/sdb1

        </screen>

      </para>

    </refsect2>

    <refsect2>

      <title>REPAIR-STORAGE</title>

      <cmdsynopsis>

        <command>repair-storage</command>

        <arg>--ignore-consistency</arg>

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

        <arg choice="req"><replaceable>storage-type</replaceable></arg>

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

      </cmdsynopsis>

      <para>

        Repairs a storage volume on a node. Only LVM volume groups can

        be repaired at this time. They have the storage type

        <quote>lvm-vg</quote>.

      </para>

      <para>

        On LVM volume groups, <command>repair-storage</command> runs

        <quote>vgreduce --removemissing</quote>.

      </para>

      <caution>

        <para>

          Running this command can lead to data loss. Use it with care.

        </para>

      </caution>

      <para>

        The <option>--ignore-consistency</option> option will ignore

        any inconsistent disks (on the nodes paired with this

        one). Use of this option is most likely to lead to data-loss.

      </para>

      <para>

        Example:

        <screen>

# gnt-node repair-storage node5.example.com lvm-vg xenvg

        </screen>

      </para>

    </refsect2>

    <refsect2>

      <title>POWERCYCLE</title>

      <cmdsynopsis>

        <command>powercycle</command>

        <arg><option>--yes</option></arg>

        <arg><option>--force</option></arg>

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

      </cmdsynopsis>

      <para>

        This commands (tries to) forcefully reboot a node. It is a

        command that can be used if the node environemnt is broken,

        such that the admin can no longer login over ssh, but the

        Ganeti node daemon is still working.

      </para>

      <para>

        Note that this command is not guaranteed to work; it depends

        on the hypervisor how effective is the reboot attempt. For

        Linux, this command require that the kernel option

        <literal>CONFIG_MAGIC_SYSRQ</literal> is enabled.

      </para>

      <para>

        The <option>--yes</option> option can be used to skip

        confirmation, while the <option>--force</option> option is

        needed if the target node is the master node.

      </para>

  </refsect1>

  &footer;

</refentry>

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