Synnefo » snf-ganeti » ganeti-local

Removing a cluster entirely

~~~~~~~~~~~~~~~~~~~~~~~~~~~

The usual method to cleanup a cluster is to run ``gnt-cluster

destroy`` however if the Ganeti installation is broken in any way then

this will not run.

It is possible in such a case to cleanup manually most if not all

traces of a cluster installation by following these steps on all of

the nodes:

1. Shutdown all instances. This depends on the virtualisation

   method used (Xen, KVM, etc.):

  - Xen: run ``xm list`` and ``xm destroy`` on all the non-Domain-0

    instances

  - KVM: kill all the KVM processes

  - chroot: kill all processes under the chroot mountpoints

2. If using DRBD, shutdown all DRBD minors (which should by at this

   time no-longer in use by instances); on each node, run ``drbdsetup

   /dev/drbdN down`` for each active DRBD minor.

3. If using LVM, cleanup the Ganeti volume group; if only Ganeti

   created logical volumes (and you are not sharing the volume group

   with the OS, for example), then simply running ``lvremove -f

   xenvg`` (replace 'xenvg' with your volume group name) should do the

   required cleanup.

4. If using file-based storage, remove recursively all files and

   directories under your file-storage directory: ``rm -rf

   /srv/ganeti/file-storage/*`` replacing the path with the correct

   path for your cluster.

5. Stop the ganeti daemons (``/etc/init.d/ganeti stop``) and kill any

   that remain alive (``pgrep ganeti`` and ``pkill ganeti``).

6. Remove the ganeti state directory (``rm -rf /var/lib/ganeti/*``),

   replacing the path with the correct path for your installation.

On the master node, remove the cluster from the master-netdev (usually

``xen-br0`` for bridged mode, otherwise ``eth0`` or similar), by

running ``ip a del $clusterip/32 dev xen-br0`` (use the correct

cluster ip and network device name).

At this point, the machines are ready for a cluster creation; in case

you want to remove Ganeti completely, you need to also undo some of

the SSH changes and log directories:

- ``rm -rf /var/log/ganeti /srv/ganeti`` (replace with the correct paths)

- remove from ``/root/.ssh`` the keys that Ganeti added (check

  the ``authorized_keys`` and ``id_dsa`` files)

- regenerate the host's SSH keys (check the OpenSSH startup scripts)

- uninstall Ganeti

Otherwise, if you plan to re-create the cluster, you can just go ahead

and rerun ``gnt-cluster init``.