========================== Block Device Quick Start

Ensure your :term:Ceph Storage Cluster is in an active + clean state before working with the :term:Ceph Block Device.

.. note:: The Ceph Block Device is also known as :term:RBD or :term:RADOS Block Device.

.. ditaa::

       /------------------\         /----------------\
       |    Admin Node    |         |   ceph-client  |
       |                  +-------->+ cCCC           |
       |    ceph-deploy   |         |      ceph      |
       \------------------/         \----------------/

You may use a virtual machine for your ceph-client node, but do not execute the following procedures on the same physical node as your Ceph Storage Cluster nodes (unless you use a VM).

Create a Block Device Pool

#. On the admin node, use the ceph tool to :ref:create a pool <createpool> (we recommend the name 'rbd').

#. On the admin node, use the rbd tool to initialize the pool for use by RBD:

.. prompt:: bash $

  rbd pool init <pool-name>

Configure a Block Device

#. On the ceph-client node, create a block device image.

.. prompt:: bash $

  rbd create foo --size 40G [-m <mon-IP>] [-k /path/to/ceph.client.admin.keyring] [-p <pool-name>]

#. On the ceph-client node, map the image to a block device.

.. prompt:: bash $

  sudo rbd map foo [-m <mon-IP>] [-k /path/to/ceph.client.admin.keyring] [-p <pool-name>]

#. Use the block device by creating a file system on the ceph-client node.

.. prompt:: bash $

  sudo mkfs.ext4 -m0 /dev/rbd/<pool-name>/foo

This may take a few moments.

#. Mount the file system on the ceph-client node.

.. prompt:: bash $

  sudo mkdir /mnt/ceph-block-device
  sudo mount /dev/rbd/<pool-name>/foo /mnt/ceph-block-device
  cd /mnt/ceph-block-device

#. Optionally configure the block device to be automatically mapped and mounted at boot (and unmounted/unmapped at shutdown) - see the :ref:rbdmap manpage <rbdmap>.

See :ref:ceph_block_device for additional details.