openstack-ansible/doc/source/developer-docs/configure-ceph.rst

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Configuring the Ceph client (optional)

Ceph is a massively scalable, open source, distributed storage system.

These links provide details on how to use Ceph with OpenStack:

• Ceph Block Devices and OpenStack
• Ceph - The De Facto Storage Backend for OpenStack (Hong Kong Summit talk)
• OpenStack Config Reference - Ceph RADOS Block Device (RBD)
• OpenStack-Ansible and Ceph Working Example

Note

Configuring Ceph storage servers is outside the scope of this documentation.

Authentication

We recommend the cephx authentication method in the Ceph config reference. OpenStack-Ansible enables cephx by default for the Ceph client. You can choose to override this setting by using the cephx Ansible variable:

cephx: False

Deploy Ceph on a trusted network if disabling cephx.

Configuration file overrides

OpenStack-Ansible provides the ceph_conf_file variable. This allows you to specify configuration file options to override the default Ceph configuration:

ceph_conf_file: |
  [global]
  fsid = 4037aa5f-abde-4378-9470-f73dbd6ceaba
  mon_initial_members = mon1.example.local,mon2.example.local,mon3.example.local
  mon_host = 172.29.244.151,172.29.244.152,172.29.244.153
  auth_cluster_required = cephx
  auth_service_required = cephx
  auth_client_required = cephx

The use of the ceph_conf_file variable is optional. By default, OpenStack-Ansible obtains a copy of ceph.conf from one of your Ceph monitors. This transfer of ceph.conf requires the OpenStack-Ansible deployment host public key to be deployed to all of the Ceph monitors. More details are available here: Deploying SSH Keys.

The following minimal example configuration sets nova and glance to use ceph pools: ephemeral-vms and images respectively. The example uses cephx authentication, and requires existing glance and cinder accounts for images and ephemeral-vms pools.

glance_default_store: rbd
nova_libvirt_images_rbd_pool: ephemeral-vms

Monitors

The Ceph Monitor maintains a master copy of the cluster map. OpenStack-Ansible provides the ceph_mons variable and expects a list of IP addresses for the Ceph Monitor servers in the deployment:

ceph_mons:
    - 172.29.244.151
    - 172.29.244.152
    - 172.29.244.153

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