== How To Install Ganeti Clusters and Instances ==

=== How To Install Ganeti Clusters ===

Suppose that you have two identical hosts running squeeze, foo.debian.org and
bar.debian.org, that will be used as nodes in a ganeti cluster.

==== install required packages ====

On each node, install the required packages:

{{{
    apt-get install fai-client ssed extlinux
    apt-get install -t squeeze-backports drbd8-utils ganeti2 ganeti-instance-debootstrap ganeti-htools
}}}

==== configure kernel modules ====

On each node, ensure that required kernel modules are loaded at boot:

{{{
    ainsl /etc/modules 'drbd minor_count=255 usermode_helper=/bin/true'
    ainsl /etc/modules 'hmac'
    ainsl /etc/modules 'tun'
}}}

==== configure networking ====

Determine a hostname for the cluster (foobar.debian.org) and assign an A record.

On each node, ensure that all nodes and the cluster itself are listed in
{{{/etc/hosts}}}.

On each node, create a bridge interface: br0.

==== create storage ====

On each node, configure lvm to ignore drbd devices and to prefer
{{{/dev/cciss}}} devices names to {{{/dev/block}}} device names
([[http://code.google.com/p/ganeti/issues/detail?id=93|why?]]):

{{{
    ssed -i \
      -e 's#^\(\s*filter\s\).*#\1= [ "a|.*|", "r|/dev/drbd[0-9]+|" ]#'
      -e 's#^\(\s*preferred_names\s\).*#\1= [ "^/dev/dm-*/", "^/dev/cciss/" ]#' \
      /etc/lvm/lvm.conf
}}}

On each node, create a volume group:

{{{
    vgcreate vg_ganeti /dev/cciss/c0d0p3
}}}

==== create kvmU symbolic links ====

{{{
    ln -s -T /boot/vmlinuz-2.6.32-5-amd64 /boot/vmlinuz-2.6-kvmU
    ln -s -T /boot/initrd.img-2.6.32-5-amd64 /boot/initrd.img-2.6-kvmU
}}}

==== instantiate the cluster ====

On the master node (foo) only:

{{{
    gnt-cluster init \
      --master-netdev br0 \
      --vg-name vg_ganeti \
      --secondary-ip 192.168.2.213 \
      --enabled-hypervisors kvm \
      --nic-parameters link=br0 \
      --mac-prefix 00:16:37 \
      --no-ssh-init \
      --no-etc-hosts \
      --hypervisor-parameters kvm:initrd_path=/boot/initrd.img-2.6-kvmU \
      foobar.debian.org
}}}

==== add slave nodes ===

For each slave node (bar), on the master node (foo):

{{{
    gnt-node add \
      --secondary-ip 192.168.2.217 \
      --no-ssh-key-check \
      --no-node-setup \
      bar.debian.org
}}}

==== verify cluster ====

On the master node (foo):

{{{
    gnt-cluster verify
}}}

=== How To Install Ganeti Instances ===

Suppose that the first guest on will be qux.debian.org.

==== define the instance ====

# add qux.debian.org entry in LDAP to establish A record
# ask hosting partner to establish PTR record as appropriate
# add qux.debian.org entry in puppet
# add qux.debian.org entry in nagios

==== create the instance ====

On the master node (foo):

{{{
    gnt-instance add \
      --node foo:bar \
      --disk-template drbd \
      --os-size 4GiB \
      --os-type debootstrap+dsa \
      --hypervisor-parameters kvm:initrd_path=,kernel_path= \
      --net 0:ip=1.2.3.4 \
      qux.debian.org
}}}