Block Device Quick Start
To use this guide, you must have executed the procedures in the StorageCluster Quick Start guide first. Ensure your Ceph Storage Cluster isin an active + clean
state before working with the Ceph BlockDevice.
Note
The Ceph Block Device is also known as RBD or RADOSBlock Device.
You may use a virtual machine for your ceph-client
node, but do notexecute the following procedures on the same physical node as your CephStorage Cluster nodes (unless you use a VM). See FAQ for details.
Install Ceph
- Verify that you have an appropriate version of the Linux kernel.See OS Recommendations for details.
- lsb_release -a
- uname -r
- On the admin node, use
ceph-deploy
to install Ceph on yourceph-client
node.
- ceph-deploy install ceph-client
- On the admin node, use
ceph-deploy
to copy the Ceph configuration fileand theceph.client.admin.keyring
to theceph-client
.
- ceph-deploy admin ceph-client
The ceph-deploy
utility copies the keyring to the /etc/ceph
directory. Ensure that the keyring file has appropriate read permissions(e.g., sudo chmod +r /etc/ceph/ceph.client.admin.keyring
).
Create a Block Device Pool
On the admin node, use the
ceph
tool to create a pool(we recommend the name ‘rbd’).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
- 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}]
- 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}]
- 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.
- 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
- Optionally configure the block device to be automatically mapped and mountedat boot (and unmounted/unmapped at shutdown) - see the rbdmap manpage.
See block devices for additional details.