Configuration

The inventory may define these hosts to run the step completely:

• clients: Set of hosts that must be ceph-client. These hosts will access to the storage cluster

• mons: Set of hosts to that must be ceph-mon. These hosts will maintain a map of the state of the cluster
  

• osds: Set of hosts to that must be ceph-osd. These hosts will interact with the logical disk to stock the data

More details in the documentation here.

The inventory must define these variables to run the step:

• configure_firewall: Boolean to configure the firewall (true by default)
• ceph_origin: Origin of the ceph installed files (must be set to distro). SEAPATH installs ceph with an installer (see the installation section)
• ceph_osd_disk: Device to stock datas (only for ceph-osd hosts), it's on this disk ceph will build a rbd. To success the CI, the path should be in /dev/disk/by-path
• cluster_network: Address block to access to cluster network
• dashboard_enabled: Boolean to enable a dashboard (must be set to false)
• devices: List of devices to use for the shared storage. All specified devices will be used entirely
• lvm_volumes: List of volumes to use for the shared storage. To use to replace devices to take a part of the device
• monitor_address: Address where the host will bind
• ntp_service_enabled: Boolean to enable the NTP service (must be set to false). SEAPATH installs a specific NTP client and configure it

• osd_pool_default_min_size: Minimal number of available OSD to ensure cluster success (best: ceil(osd_pool_default_size / 2.0))

• osd_pool_default_size: Number of OSD in the cluster

• public_network: Address block to access to public network

Volumes specifications

If lvm_volumes is defined, the devices variables is ignored.

When a volume is defined for the shared storage, some fields should be set for seapath-ansible and ceph-ansible.

• data: Logical volume to use for the shared storage (ceph-ansible variable)
• data_vg: Volume group where the logical volume is (ceph-ansible variable)
• data_size: Size of the logical volume (in megabytes by default). Change the unit with the appropriate suffix
• device: Device to use to create the logical volume
• device_number: Number of the partition
• device_size: Size of the partition to stock the logical volume

Override configuration

ceph offers to override the configuration with ceph_conf_override:

Override global configuration

• mon_osd_min_down_reporters: (must be set to 1)
• osd_crush_chooseleaf_type: (must be set to 1)
• osd_pool_default_min_size: Minimal number of available OSD to ensure cluster success (best: ceil(osd_pool_default_size / 2.0))
• osd_pool_default_pg_num: (must be set to 128)
• osd_pool_default_pgp_num: (must be set to 128)
• osd_pool_default_size: Number of OSD in the cluster

Override mon configuration

• auth_allow_insecure_global_id_reclaim: Boolean (must be set to false)

Override osd configuration

• osd_max_pg_log_entries: (must be set to 500)
• osd_min_pg_log_entries: (must be set to 500)
• osd_memory_target: Size of the memory (in bytes)

Ceph provides ansible rules to configure the software, you can read the documentation here.

RADOS Block Devices

During this step, ceph will build a RADOS block device (RBD) from ceph_osd_disk. A storage entry (a pool) will be automatically generated for libvirt. When the service will be started, the hypervisor should be used to launch VMs.

On the ceph_osd_disk of all machines, there are the same data.

This disk will be used with the librbd library provided by ceph.

More details here.