=====================
 Preflight Checklist
=====================

.. versionadded:: 0.60

Thank you for trying Ceph! Petabyte-scale data clusters are quite an
undertaking. Before delving deeper into Ceph, we recommend setting up a two-node
demo cluster to explore some of the functionality. This **Preflight Checklist**
will help you prepare an admin node and a server node for use with
``ceph-deploy``.

.. ditaa::
           /----------------\         /----------------\
           |   Admin Node   |<------->|   Server Node  |
           | cCCC           |         | cCCC           |
           \----------------/         \----------------/


Before you can deploy Ceph using ``ceph-deploy``, you need to ensure that you
have a few things set up first on your admin node and on nodes running Ceph
daemons.


Install an Operating System
===========================

Install a recent release of Debian or Ubuntu (e.g., 12.04, 12.10, 13.04) on your
nodes. For additional details on operating systems or to use other operating
systems other than Debian or Ubuntu, see `OS Recommendations`_.


Install an SSH Server
=====================

The ``ceph-deploy`` utility requires ``ssh``, so your server node(s) require an
SSH server. ::

	sudo apt-get install openssh-server


Create a User
=============

Create a user on nodes running Ceph daemons.

.. tip:: We recommend a username that brute force attackers won't
   guess easily (e.g., something other than ``root``, ``ceph``, etc).

::

	ssh user@ceph-server
	sudo useradd -d /home/ceph -m ceph
	sudo passwd ceph


``ceph-deploy`` installs packages onto your nodes. This means that
the user you create requires passwordless ``sudo`` privileges.

.. note:: We **DO NOT** recommend enabling the ``root`` password
   for security reasons.

To provide full privileges to the user, add the following to
``/etc/sudoers.d/ceph``. ::

	echo "ceph ALL = (root) NOPASSWD:ALL" | sudo tee /etc/sudoers.d/ceph
	sudo chmod 0440 /etc/sudoers.d/ceph


Configure SSH
=============

Configure your admin machine with password-less SSH access to each node
running Ceph daemons (leave the passphrase empty). ::

	ssh-keygen
	Generating public/private key pair.
	Enter file in which to save the key (/ceph-client/.ssh/id_rsa):
	Enter passphrase (empty for no passphrase):
	Enter same passphrase again:
	Your identification has been saved in /ceph-client/.ssh/id_rsa.
	Your public key has been saved in /ceph-client/.ssh/id_rsa.pub.

Copy the key to each node running Ceph daemons::

	ssh-copy-id ceph@ceph-server

Modify your ~/.ssh/config file of your admin node so that it defaults
to logging in as the user you created when no username is specified. ::

	Host ceph-server
		Hostname ceph-server.fqdn-or-ip-address.com
		User ceph

.. note:: Do not call ceph-deploy with ``sudo`` or run as ``root`` if you are
          login in as a different user (as in the ssh config above) because it
          will not issue ``sudo`` commands needed on the remote host.

Install ceph-deploy
===================

To install ``ceph-deploy``, execute the following::

	wget -q -O- 'https://ceph.com/git/?p=ceph.git;a=blob_plain;f=keys/release.asc' | sudo apt-key add -
	echo deb http://ceph.com/debian-dumpling/ $(lsb_release -sc) main | sudo tee /etc/apt/sources.list.d/ceph.list
	sudo apt-get update
	sudo apt-get install ceph-deploy


Ensure Connectivity
===================

Ensure that your admin node has connectivity to the network and to your Server
node (e.g., ensure ``iptables``, ``ufw`` or other tools that may prevent
connections, traffic forwarding, etc. to allow what you need).

.. tip:: The ``ceph-deploy`` tool is new and you may encounter some issues
   without  effective error messages.

Once you have completed this pre-flight checklist, you are ready to begin using
``ceph-deploy``.


Hostname Resolution
===================

Ensure that your admin node can resolve the server node's hostname. ::

	ping {server-node}

If you execute ``ceph-deploy`` against the localhost, ``ceph-deploy``
must be able to resolve its IP address. Consider adding the IP address
to your ``/etc/hosts`` file such that it resolves to the hostname. ::

	hostname
	host -4 {hostname}
	sudo vim /etc/hosts

	{ip-address} {hostname}

	ceph-deploy {command} {hostname}

.. tip:: The ``ceph-deploy`` tool will not resolve to ``localhost``. Use
   the hostname.

Summary
=======

Once you have passwordless ``ssh`` connectivity, passwordless ``sudo``,
installed ``ceph-deploy``, and you have ensured appropriate connectivity,
proceed to the `Storage Cluster Quick Start`_.

.. tip:: The ``ceph-deploy`` utility can install Ceph packages on remote
   machines from the admin node!

.. _Storage Cluster Quick Start: ../quick-ceph-deploy
.. _OS Recommendations: ../../install/os-recommendations