External Ceph

Kolla Ansible does not provide support for provisioning and configuring a Ceph cluster directly. Instead, administrators should use a tool dedicated to this purpose, such as:

The desired pool(s) and keyrings should then be created via the Ceph CLI or similar.

Requirements

  • An existing installation of Ceph

  • Existing Ceph storage pools

  • Existing credentials in Ceph for OpenStack services to connect to Ceph (Glance, Cinder, Nova, Gnocchi, Manila)

Refer to https://docs.ceph.com/en/latest/rbd/rbd-openstack/ for details on creating the pool and keyrings with appropriate permissions for each service.

Configuring External Ceph

Ceph integration is configured for different OpenStack services independently.

Glance

Ceph RBD can be used as a storage backend for Glance images. Configuring Glance for Ceph includes the following steps:

  1. Enable Glance Ceph backend in globals.yml:

    glance_backend_ceph: "yes"
    
  2. Configure Ceph authentication details in /etc/kolla/globals.yml:

    • ceph_glance_keyring (default: ceph.client.glance.keyring)

    • ceph_glance_user (default: glance)

    • ceph_glance_pool_name (default: images)

  3. Copy Ceph configuration file to /etc/kolla/config/glance/ceph.conf

    [global]
    fsid = 1d89fec3-325a-4963-a950-c4afedd37fe3
    mon_initial_members = ceph-0
    mon_host = 192.168.0.56
    auth_cluster_required = cephx
    auth_service_required = cephx
    auth_client_required = cephx
    
  4. Copy Ceph keyring to /etc/kolla/config/glance/<ceph_glance_keyring>

Cinder

Ceph RBD can be used as a storage backend for Cinder volumes. Configuring Cinder for Ceph includes following steps:

  1. When using external Ceph, there may be no nodes defined in the storage group. This will cause Cinder and related services relying on this group to fail. In this case, operator should add some nodes to the storage group, all the nodes where cinder-volume and cinder-backup will run:

    [storage]
    control01
    
  2. Enable Cinder Ceph backend in globals.yml:

    cinder_backend_ceph: "yes"
    
  3. Configure Ceph authentication details in /etc/kolla/globals.yml:

    • ceph_cinder_keyring (default: ceph.client.cinder.keyring)

    • ceph_cinder_user (default: cinder)

    • ceph_cinder_pool_name (default: volumes)

    • ceph_cinder_backup_keyring (default: ceph.client.cinder-backup.keyring)

    • ceph_cinder_backup_user (default: cinder-backup)

    • ceph_cinder_backup_pool_name (default: backups)

  4. Copy Ceph configuration file to /etc/kolla/config/cinder/ceph.conf

    Separate configuration options can be configured for cinder-volume and cinder-backup by adding ceph.conf files to /etc/kolla/config/cinder/cinder-volume and /etc/kolla/config/cinder/cinder-backup respectively. They will be merged with /etc/kolla/config/cinder/ceph.conf.

  5. Copy Ceph keyring files to:

    • /etc/kolla/config/cinder/cinder-volume/<ceph_cinder_keyring>

    • /etc/kolla/config/cinder/cinder-backup/<ceph_cinder_keyring>

    • /etc/kolla/config/cinder/cinder-backup/<ceph_cinder_backup_keyring>

Note

cinder-backup requires two keyrings for accessing volumes and backup pool.

Nova must also be configured to allow access to Cinder volumes:

  1. Configure Ceph authentication details in /etc/kolla/globals.yml:

    • ceph_cinder_keyring (default: ceph.client.cinder.keyring)

  2. Copy Ceph keyring file(s) to:

    • /etc/kolla/config/nova/<ceph_cinder_keyring>

Nova

Ceph RBD can be used as a storage backend for Nova instance ephemeral disks. This avoids the requirement for local storage for instances on compute nodes. It improves the performance of migration, since instances’ ephemeral disks do not need to be copied between hypervisors.

Configuring Nova for Ceph includes following steps:

  1. Enable Nova Ceph backend in globals.yml:

    nova_backend_ceph: "yes"
    
  2. Configure Ceph authentication details in /etc/kolla/globals.yml:

    • ceph_nova_keyring (by default it’s the same as ceph_cinder_keyring)

    • ceph_nova_user (by default it’s the same as ceph_cinder_user)

    • ceph_nova_pool_name (default: vms)

  3. Copy Ceph configuration file to /etc/kolla/config/nova/ceph.conf

  4. Copy Ceph keyring file(s) to:

    • /etc/kolla/config/nova/<ceph_nova_keyring>

    Note

    If you are using a Ceph deployment tool that generates separate Ceph keys for Cinder and Nova, you will need to override ceph_nova_keyring and ceph_nova_user to match.

Gnocchi

Ceph object storage can be used as a storage backend for Gnocchi metrics. Configuring Gnocchi for Ceph includes following steps:

  1. Enable Gnocchi Ceph backend in globals.yml:

    gnocchi_backend_storage: "ceph"
    
  2. Configure Ceph authentication details in /etc/kolla/globals.yml:

    • ceph_gnocchi_keyring (default: ceph.client.gnocchi.keyring)

    • ceph_gnocchi_user (default: gnocchi)

    • ceph_gnocchi_pool_name (default: gnocchi)

  3. Copy Ceph configuration file to /etc/kolla/config/gnocchi/ceph.conf

  4. Copy Ceph keyring to /etc/kolla/config/gnocchi/<ceph_gnocchi_keyring>

Manila

CephFS can be used as a storage backend for Manila shares. Configuring Manila for Ceph includes following steps:

  1. Enable Manila Ceph backend in globals.yml:

    enable_manila_backend_cephfs_native: "yes"
    
  2. Configure Ceph authentication details in /etc/kolla/globals.yml:

    • ceph_manila_keyring (default: ceph.client.manila.keyring)

    • ceph_manila_user (default: manila)

    Note

    Required Ceph identity caps for manila user are documented in CephFS Native driver.

  3. Copy Ceph configuration file to /etc/kolla/config/manila/ceph.conf

  4. Copy Ceph keyring to /etc/kolla/config/manila/<ceph_manila_keyring>

  5. Setup Manila in the usual way

For more details on the rest of the Manila setup, such as creating the share type default_share_type, please see Manila in Kolla.

For more details on the CephFS Native driver, please see CephFS Native driver.