quick-rbd.rst

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). See FAQ for details.

Create a Block Device Pool

1. On the admin node, use the ceph tool to create a pool (we recommend the name 'rbd').

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

   rbd pool init <pool-name>
   

Configure a Block Device

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

   rbd create foo --size 4096 --image-feature layering [-m {mon-IP}] [-k /path/to/ceph.client.admin.keyring] [-p {pool-name}]
   

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

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

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

   sudo mkfs.ext4 -m0 /dev/rbd/{pool-name}/foo
   
   This may take a few moments.
   

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

   sudo mkdir /mnt/ceph-block-device
   sudo mount /dev/rbd/{pool-name}/foo /mnt/ceph-block-device
   cd /mnt/ceph-block-device
   

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

See block devices for additional details.