UPGRADE

Upgrade notes
=============

.. highlight:: shell-example

This document details the steps needed to upgrade a cluster to newer versions
of Ganeti.

As a general rule the node daemons need to be restarted after each software
upgrade; if using the provided example init.d script, this means running the
following command on all nodes::

    $ /etc/init.d/ganeti restart

2.11 and above
--------------

Starting from 2.10 onwards, Ganeti has support for parallely installed versions
and automated upgrades. The default configuration for 2.11 and higher already is
to install as a parallel version without changing the running version. If both
versions, the installed one and the one to upgrade to, are 2.10 or higher, the
actual switch of the live version can be carried out by the following command
on the master node.::

   $ gnt-cluster upgrade --to 2.11

This will carry out the steps described below in the section on upgrades from
2.1 and above. Downgrades to the previous minor version can be done in the same
way, specifiying the smaller version on the ``--to`` argument.

Note that ``gnt-cluster upgrade`` only manages the actual switch between
versions as described below on upgrades from 2.1 and above. It does not install
or remove any binaries. Having the new binaries installed is a prerequisite of
calling ``gnt-cluster upgrade`` (and the command will abort if the prerequisite
is not met). The old binaries can be used to downgrade back to the previous
version; once the system administrator decides that going back to the old
version is not needed any more, they can be removed. Addition and removal of
the Ganeti binaries should happen in the same way as for all other binaries on
your system.


2.13
----

When upgrading to 2.13, first apply the instructions of ``2.11 and
above``. 2.13 comes with the new feature of enhanced SSH security
through individual SSH keys. This features needs to be enabled
after the upgrade by::

   $ gnt-cluster renew-crypto --new-ssh-keys --no-ssh-key-check

Note that new SSH keys are generated automatically without warning when
upgrading with ``gnt-cluster upgrade``.

If you instructed Ganeti to not touch the SSH setup (by using the
``--no-ssh-init`` option of ``gnt-cluster init``, the changes in the
handling of SSH keys will not affect your cluster.

If you want to be prompted for each newly created SSH key, leave out
the ``--no-ssh-key-check`` option in the command listed above.

Note that after a downgrade from 2.13 to 2.12, the individual SSH keys
will not get removed automatically. This can lead to reachability
errors under very specific circumstances (Issue 1008). In case you plan
on keeping 2.12 for a while and not upgrade to 2.13 again soon, we recommend
to replace all SSH key pairs of non-master nodes' with the master node's SSH
key pair.


2.12
----

Due to issue #1094 in Ganeti 2.11 and 2.12 up to version 2.12.4, we
advise to rerun 'gnt-cluster renew-crypto --new-node-certificates'
after an upgrade to 2.12.5 or higher.


2.11
----

When upgrading to 2.11, first apply the instructions of ``2.11 and
above``. 2.11 comes with the new feature of enhanced RPC security
through client certificates. This features needs to be enabled after the
upgrade by::

   $ gnt-cluster renew-crypto --new-node-certificates

Note that new node certificates are generated automatically without
warning when upgrading with ``gnt-cluster upgrade``.


2.1 and above
-------------

Starting with Ganeti 2.0, upgrades between revisions (e.g. 2.1.0 to 2.1.1)
should not need manual intervention. As a safety measure, minor releases (e.g.
2.1.3 to 2.2.0) require the ``cfgupgrade`` command for changing the
configuration version. Below you find the steps necessary to upgrade between
minor releases.

To run commands on all nodes, the `distributed shell (dsh)
<http://www.netfort.gr.jp/~dancer/software/dsh.html.en>`_ can be used, e.g.
``dsh -M -F 8 -f /var/lib/ganeti/ssconf_online_nodes gnt-cluster --version``.

#. Ensure no jobs are running (master node only)::

    $ gnt-job list

#. Pause the watcher for an hour (master node only)::

    $ gnt-cluster watcher pause 1h

#. Stop all daemons on all nodes::

    $ /etc/init.d/ganeti stop

#. Backup old configuration (master node only)::

    $ tar czf /var/lib/ganeti-$(date +\%FT\%T).tar.gz -C /var/lib ganeti

    (``/var/lib/ganeti`` can also contain exported instances, so make sure to
    backup only files you are interested in. Use ``--exclude export`` for
    example)

#. Install new Ganeti version on all nodes
#. Run cfgupgrade on the master node::

    $ /usr/lib/ganeti/tools/cfgupgrade --verbose --dry-run
    $ /usr/lib/ganeti/tools/cfgupgrade --verbose

   (``cfgupgrade`` supports a number of parameters, run it with
   ``--help`` for more information)

#. Upgrade the directory permissions on all nodes::

    $ /usr/lib/ganeti/ensure-dirs --full-run

#. Create the (missing) required users and make users part of the required
   groups on all nodes::

    $ /usr/lib/ganeti/tools/users-setup

   This will ask for confirmation. To execute directly, add the ``--yes-do-it``
   option.

#. Restart daemons on all nodes::

    $ /etc/init.d/ganeti restart

#. Re-distribute configuration (master node only)::

    $ gnt-cluster redist-conf

#. If you use file storage, check that the ``/etc/ganeti/file-storage-paths``
   is correct on all nodes. For security reasons it's not copied
   automatically, but it can be copied manually via::

   $ gnt-cluster copyfile /etc/ganeti/file-storage-paths

#. Restart daemons again on all nodes::

    $ /etc/init.d/ganeti restart

#. Enable the watcher again (master node only)::

    $ gnt-cluster watcher continue

#. Verify cluster (master node only)::

    $ gnt-cluster verify

Reverting an upgrade
~~~~~~~~~~~~~~~~~~~~

For going back between revisions (e.g. 2.1.1 to 2.1.0) no manual
intervention is required, as for upgrades.

Starting from version 2.8, ``cfgupgrade`` supports ``--downgrade``
option to bring the configuration back to the previous stable version.
This is useful if you upgrade Ganeti and after some time you run into
problems with the new version. You can downgrade the configuration
without losing the changes made since the upgrade. Any feature not
supported by the old version will be removed from the configuration, of
course, but you get a warning about it. If there is any new feature and
you haven't changed from its default value, you don't have to worry
about it, as it will get the same value whenever you'll upgrade again.

Automatic downgrades
....................

From version 2.11 onwards, downgrades can be done by using the
``gnt-cluster upgrade`` command.::

  gnt-cluster upgrade --to 2.10

Manual downgrades
.................

The procedure is similar to upgrading, but please notice that you have to
revert the configuration **before** installing the old version.

#. Ensure no jobs are running (master node only)::

    $ gnt-job list

#. Pause the watcher for an hour (master node only)::

    $ gnt-cluster watcher pause 1h

#. Stop all daemons on all nodes::

    $ /etc/init.d/ganeti stop

#. Backup old configuration (master node only)::

    $ tar czf /var/lib/ganeti-$(date +\%FT\%T).tar.gz -C /var/lib ganeti

#. Run cfgupgrade on the master node::

    $ /usr/lib/ganeti/tools/cfgupgrade --verbose --downgrade --dry-run
    $ /usr/lib/ganeti/tools/cfgupgrade --verbose --downgrade

   You may want to copy all the messages about features that have been
   removed during the downgrade, in case you want to restore them when
   upgrading again.

#. Install the old Ganeti version on all nodes

   NB: in Ganeti 2.8, the ``cmdlib.py`` file was split into a series of files
   contained in the ``cmdlib`` directory. If Ganeti is installed from sources
   and not from a package, while downgrading Ganeti to a pre-2.8
   version it is important to remember to remove the ``cmdlib`` directory
   from the directory containing the Ganeti python files (which usually is
   ``${PREFIX}/lib/python${VERSION}/dist-packages/ganeti``).
   A simpler upgrade/downgrade procedure will be made available in future
   versions of Ganeti.

#. Restart daemons on all nodes::

    $ /etc/init.d/ganeti restart

#. Re-distribute configuration (master node only)::

    $ gnt-cluster redist-conf

#. Restart daemons again on all nodes::

    $ /etc/init.d/ganeti restart

#. Enable the watcher again (master node only)::

    $ gnt-cluster watcher continue

#. Verify cluster (master node only)::

    $ gnt-cluster verify

Specific tasks for 2.11 to 2.10 downgrade
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

After running ``cfgupgrade``, the ``client.pem`` and
``ssconf_master_candidates_certs`` files need to be removed
from Ganeti's data directory on all nodes. While this step is
not necessary for 2.10 to run cleanly, leaving them will cause
problems when upgrading again after the downgrade.

2.0 releases
------------

2.0.3 to 2.0.4
~~~~~~~~~~~~~~

No changes needed except restarting the daemon; but rollback to 2.0.3 might
require configuration editing.

If you're using Xen-HVM instances, please double-check the network
configuration (``nic_type`` parameter) as the defaults might have changed:
2.0.4 adds any missing configuration items and depending on the version of the
software the cluster has been installed with, some new keys might have been
added.

2.0.1 to 2.0.2/2.0.3
~~~~~~~~~~~~~~~~~~~~

Between 2.0.1 and 2.0.2 there have been some changes in the handling of block
devices, which can cause some issues. 2.0.3 was then released which adds two
new options/commands to fix this issue.

If you use DRBD-type instances and see problems in instance start or
activate-disks with messages from DRBD about "lower device too small" or
similar, it is recoomended to:

#. Run ``gnt-instance activate-disks --ignore-size $instance`` for each
   of the affected instances
#. Then run ``gnt-cluster repair-disk-sizes`` which will check that
   instances have the correct disk sizes

1.2 to 2.0
----------

Prerequisites:

- Ganeti 1.2.7 is currently installed
- All instances have been migrated from DRBD 0.7 to DRBD 8.x (i.e. no
  ``remote_raid1`` disk template)
- Upgrade to Ganeti 2.0.0~rc2 or later (~rc1 and earlier don't have the needed
  upgrade tool)

In the below steps, replace :file:`/var/lib` with ``$libdir`` if Ganeti was not
installed with this prefix (e.g. :file:`/usr/local/var`). Same for
:file:`/usr/lib`.

Execution (all steps are required in the order given):

#. Make a backup of the current configuration, for safety::

    $ cp -a /var/lib/ganeti /var/lib/ganeti-1.2.backup

#. Stop all instances::

    $ gnt-instance stop --all

#. Make sure no DRBD device are in use, the following command should show no
   active minors::

    $ gnt-cluster command grep cs: /proc/drbd | grep -v cs:Unconf

#. Stop the node daemons and rapi daemon on all nodes (note: should be logged
   in not via the cluster name, but the master node name, as the command below
   will remove the cluster ip from the master node)::

    $ gnt-cluster command /etc/init.d/ganeti stop

#. Install the new software on all nodes, either from packaging (if available)
   or from sources; the master daemon will not start but give error messages
   about wrong configuration file, which is normal
#. Upgrade the configuration file::

    $ /usr/lib/ganeti/tools/cfgupgrade12 -v --dry-run
    $ /usr/lib/ganeti/tools/cfgupgrade12 -v

#. Make sure ``ganeti-noded`` is running on all nodes (and start it if
   not)
#. Start the master daemon::

    $ ganeti-masterd

#. Check that a simple node-list works::

    $ gnt-node list

#. Redistribute updated configuration to all nodes::

    $ gnt-cluster redist-conf
    $ gnt-cluster copyfile /var/lib/ganeti/known_hosts

#. Optional: if needed, install RAPI-specific certificates under
   :file:`/var/lib/ganeti/rapi.pem` and run::

    $ gnt-cluster copyfile /var/lib/ganeti/rapi.pem

#. Run a cluster verify, this should show no problems::

    $ gnt-cluster verify

#. Remove some obsolete files::

    $ gnt-cluster command rm /var/lib/ganeti/ssconf_node_pass
    $ gnt-cluster command rm /var/lib/ganeti/ssconf_hypervisor

#. Update the xen pvm (if this was a pvm cluster) setting for 1.2
   compatibility::

    $ gnt-cluster modify -H xen-pvm:root_path=/dev/sda

#. Depending on your setup, you might also want to reset the initrd parameter::

    $ gnt-cluster modify -H xen-pvm:initrd_path=/boot/initrd-2.6-xenU

#. Reset the instance autobalance setting to default::

    $ for i in $(gnt-instance list -o name --no-headers); do \
       gnt-instance modify -B auto_balance=default $i; \
      done

#. Optional: start the RAPI demon::

    $ ganeti-rapi

#. Restart instances::

    $ gnt-instance start --force-multiple --all

At this point, ``gnt-cluster verify`` should show no errors and the migration
is complete.

1.2 releases
------------

1.2.4 to any other higher 1.2 version
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

No changes needed. Rollback will usually require manual edit of the
configuration file.

1.2.3 to 1.2.4
~~~~~~~~~~~~~~

No changes needed. Note that going back from 1.2.4 to 1.2.3 will require manual
edit of the configuration file (since we added some HVM-related new
attributes).

1.2.2 to 1.2.3
~~~~~~~~~~~~~~

No changes needed. Note that the drbd7-to-8 upgrade tool does a disk format
change for the DRBD metadata, so in theory this might be **risky**. It is
advised to have (good) backups before doing the upgrade.

1.2.1 to 1.2.2
~~~~~~~~~~~~~~

No changes needed.

1.2.0 to 1.2.1
~~~~~~~~~~~~~~

No changes needed. Only some bugfixes and new additions that don't affect
existing clusters.

1.2.0 beta 3 to 1.2.0
~~~~~~~~~~~~~~~~~~~~~

No changes needed.

1.2.0 beta 2 to beta 3
~~~~~~~~~~~~~~~~~~~~~~

No changes needed. A new version of the debian-etch-instance OS (0.3) has been
released, but upgrading it is not required.

1.2.0 beta 1 to beta 2
~~~~~~~~~~~~~~~~~~~~~~

Beta 2 switched the config file format to JSON. Steps to upgrade:

#. Stop the daemons (``/etc/init.d/ganeti stop``) on all nodes
#. Disable the cron job (default is :file:`/etc/cron.d/ganeti`)
#. Install the new version
#. Make a backup copy of the config file
#. Upgrade the config file using the following command::

    $ /usr/share/ganeti/cfgupgrade --verbose /var/lib/ganeti/config.data

#. Start the daemons and run ``gnt-cluster info``, ``gnt-node list`` and
   ``gnt-instance list`` to check if the upgrade process finished successfully

The OS definition also need to be upgraded. There is a new version of the
debian-etch-instance OS (0.2) that goes along with beta 2.

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