Synnefo » snf-ganeti » ganeti-local

  <para>Documents Ganeti version 2.0</para>

    <para>

      Ganeti is a virtualization cluster management software. You are

      expected to be a system administrator familiar with your Linux

      distribution and the Xen or KVM virtualization environments

      before using it.

    <para>

      The various components of Ganeti all have man pages and

      interactive help. This manual though will help you getting

      familiar with the system by explaining the most common

      operations, grouped by related use.

    <para>

      After a terminology glossary and a section on the prerequisites

      needed to use this manual, the rest of this document is divided

      in three main sections, which group different features of

      Ganeti:

        <synopsis>gnt-instance add -n <replaceable>TARGET_NODE<optional>:SECONDARY_NODE</optional></replaceable> -o <replaceable>OS_TYPE</replaceable> -t <replaceable>DISK_TEMPLATE</replaceable> <replaceable>INSTANCE_NAME</replaceable></synopsis>

        usually to an address in the same subnet as the cluster

            <simpara>The disk size (<option>-s</option>) for a

            single-disk instance, or multiple <option>--disk

            <replaceable>N</replaceable>:size=<replaceable>SIZE</replaceable></option>

            options for multi-instance disks</simpara>

          <simpara>The memory size (<option>-B memory</option>)</simpara>

          <simpara>The number of virtual CPUs (<option>-B vcpus</option>)</simpara>

            <para>

              Arguments for the NICs of the instance; by default, a

              single-NIC instance is created. The IP and/or bridge of

              the NIC can be changed via <option>--nic

              0:ip=<replaceable>IP</replaceable>,bridge=<replaceable>BRIDGE</replaceable></option>

            </para>

          <term>file</term>

          <listitem>

            <para>The instance will use plain files as backend for its

            disks.  No redundancy is provided, and this is somewhat

            more difficult to configure for high performance.</para>

          </listitem>

        </varlistentry>

        <varlistentry>

        Removing an instance is even easier than creating one. This

        operation is irrereversible and destroys all the contents of

        your instance. Use with care:

      <title>Live migrating an instance</title>

      <para>

        If an instance is built in highly available mode, it currently

        runs and both its nodes are running fine, you can at migrate

        it over to its secondary node, without dowtime. On the master

        node you need to run:

        <synopsis>gnt-instance migrate <replaceable>INSTANCE_NAME</replaceable></synopsis>

      </para>

    </sect2>

    <sect2>

        <synopsis>gnt-instance replace-disks <option>-n <replaceable>NODE</replaceable></option> <replaceable>INSTANCE_NAME</replaceable></synopsis>

gnt-cluster verify-disks

  <para>Documents Ganeti version 2.0</para>

      Xen or KVM. This document explains how to bootstrap a Ganeti

      node (Xen <literal>dom0</literal>), create a running cluster and

      install virtual instance (Xen <literal>domU</literal>).  You

      need to repeat most of the steps in this document for every node

      you want to install, but of course we recommend creating some

      distribution-agnostic.  This documentation will use Debian Lenny

      your distribution, its package management system, and Xen or KVM

      before trying to use Ganeti.

        will then host your instance filesystems, if you want to use

        all Ganeti features. The volume group name Ganeti 2.0 uses (by

        default) is <emphasis>xenvg</emphasis>.

      </para>

      <para>

        You can also use file-based storage only, without LVM, but

        this is not detailed in this document.

            Note that Debian Lenny configures the hostname differently

        different virtualization environments in mind the only two

        currently useable on a live system are <ulink

        url="http://xen.xensource.com/">Xen</ulink> and KVM. Supported

        you wish, following their manual. For KVM, make sure you have

        a KVM-enabled kernel and the KVM tools.

        After installing either hypervisor, you need to reboot into

        your new system. On some distributions this might involve

        it automatically when you install the respective kernels.

        Under Debian Lenny or Etch you can install the relevant

        <literal>xen-linux-system</literal> package, which will pull

        in both the hypervisor and the relevant kernel. Also, if you

        are installing a 32-bit Lenny/Etch, you should install the

        <computeroutput>libc6-xen</computeroutput> package (run

        <computeroutput>apt-get install libc6-xen</computeroutput>).

          memory (<constant>512MiB</constant> or

          <constant>1GiB</constant> is reasonable) and that memory

          ballooning is disabled in the file

            <userinput>dom0_mem=1024M</userinput> like this:

# xenhopt=dom0_mem=1024M

          If you want to run HVM instances too with Ganeti and want

          VNC access to the console of your instances, set the

          following two entries in

        It's recommended to have at least version <literal>8.0.12</literal>.

apt-get install drbd8-source drbd8-utils

  python python-pyopenssl openssl python-pyparsing python-simplejson

        System installation script. An example OS that works under

        Debian and can install Debian and Ubuntu instace OSes is

        the installation procedure (replace <constant>0.7</constant>

cd /usr/local/src/

wget http://ganeti.googlecode.com/files/ganeti-instance-debootstrap-0.7.tar.gz

tar xzf ganeti-instance-debootstrap-0.7.tar.gz

cd ganeti-instance-debootstrap-0.7

./configure

make

make install

        all nodes. Also, if the OS is configured to partition the

        instance's disk in

        <filename>/etc/default/ganeti-instance-debootstrap</filename>,

        you will need <command>kpartx</command> installed.

          <screen>apt-get install debootstrap dump kpartx</screen>

      <para>

        The last step is to initialize the cluster. After you've

        repeated the above process on all of your nodes, choose one as

        the master, and execute:

        for this must resolve to an IP address reserved <emphasis

        role="strong">exclusively</emphasis> for this purpose.

        <option>--enabled-hypervisors=xen-hvm</option> option to

        enable the HVM hypervisor (you can also add

        <userinput>,xen-pvm</userinput> to enable the PVM one

        too). You will also need to create the VNC cluster password

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

        To setup the cluster for KVM-only usage (KVM and Xen cannot be

        mixed), pass <option>--enabled-hypervisors=kvm</option> to the

        init command.

      </para>

      <para>

gnt-instance add --node=node1 -o debootstrap -t plain inst1.example.com

# gnt-instance add -t drbd -n node1:node2 -o debootstrap instance2