rbd-ko.rst

Kernel Module Operations

.. index:: Ceph Block Device; kernel module

Important

To use kernel module operations, you must have a running Ceph cluster.

Get a List of Images

To mount a block device image, first return a list of the images.

rbd list

Map a Block Device

Use rbd to map an image name to a kernel module. You must specify the image name, the pool name, and the user name. rbd will load RBD kernel module on your behalf if it's not already loaded.

sudo rbd device map {pool-name}/{image-name} --id {user-name}

For example:

sudo rbd device map rbd/myimage --id admin

If you use cephx authentication, you must also specify a secret. It may come from a keyring or a file containing the secret.

sudo rbd device map rbd/myimage --id admin --keyring /path/to/keyring
sudo rbd device map rbd/myimage --id admin --keyfile /path/to/file

Show Mapped Block Devices

To show block device images mapped to kernel modules with the rbd, specify device list arguments.

rbd device list

Unmapping a Block Device

To unmap a block device image with the rbd command, specify the device unmap arguments and the device name (i.e., by convention the same as the block device image name).

sudo rbd device unmap /dev/rbd/{poolname}/{imagename}

For example:

sudo rbd device unmap /dev/rbd/rbd/foo