Red Hat Ceph Storage is a distributed data object store designed to provide excellent performance, reliability, and scalability. Distributed object stores are the future of storage, because they accommodate unstructured data, and because clients can use modern object interfaces and legacy interfaces simultaneously. At the heart of every Ceph deployment is the Ceph Storage cluster, which consists of two types of daemons:

For more information about Red Hat Ceph Storage, see the Red Hat Ceph Storage Architecture Guide.

This guide provides instructions on integrating an existing Ceph Storage cluster with an overcloud. This means the director configures the overcloud to use the Ceph Storage cluster for storage needs. You manage and scale the cluster itself outside of the Overcloud configuration.

To help avoid overcloud deployment failures, validate that the required packages exist on your servers.

$ ansible-playbook -i /usr/bin/tripleo-ansible-inventory /usr/share/openstack-tripleo-validations/validations/ceph-ansible-installed.yaml

ansible-playbook -i /usr/bin/tripleo-ansible-inventory /usr/share/openstack-tripleo-validations/validations/ceph-dependencies-installed.yaml

The Ceph client key and file system ID will both be used later in Chapter 3, Integrating with the Existing Ceph Cluster.

Log into the director host as the stack user and run the following command to initialize your director configuration:

$ source ~/stackrc

This sets up environment variables containing authentication details to access the director’s CLI tools.

A node definition template (instackenv.json) is a JSON format file and contains the hardware and power management details for registering nodes. For example:

{
    "nodes":[
        {
            "mac":[
                "bb:bb:bb:bb:bb:bb"
            ],
            "cpu":"4",
            "memory":"6144",
            "disk":"40",
            "arch":"x86_64",
            "pm_type":"pxe_ipmitool",
            "pm_user":"admin",
            "pm_password":"p@55w0rd!",
            "pm_addr":"192.0.2.205"
        },
        {
            "mac":[
                "cc:cc:cc:cc:cc:cc"
            ],
            "cpu":"4",
            "memory":"6144",
            "disk":"40",
            "arch":"x86_64",
            "pm_type":"pxe_ipmitool",
            "pm_user":"admin",
            "pm_password":"p@55w0rd!",
            "pm_addr":"192.0.2.206"
        },
        {
            "mac":[
                "dd:dd:dd:dd:dd:dd"
            ],
            "cpu":"4",
            "memory":"6144",
            "disk":"40",
            "arch":"x86_64",
            "pm_type":"pxe_ipmitool",
            "pm_user":"admin",
            "pm_password":"p@55w0rd!",
            "pm_addr":"192.0.2.207"
        },
        {
            "mac":[
                "ee:ee:ee:ee:ee:ee"
            ],
            "cpu":"4",
            "memory":"6144",
            "disk":"40",
            "arch":"x86_64",
            "pm_type":"pxe_ipmitool",
            "pm_user":"admin",
            "pm_password":"p@55w0rd!",
            "pm_addr":"192.0.2.208"
        }
        {
            "mac":[
                "ff:ff:ff:ff:ff:ff"
            ],
            "cpu":"4",
            "memory":"6144",
            "disk":"40",
            "arch":"x86_64",
            "pm_type":"pxe_ipmitool",
            "pm_user":"admin",
            "pm_password":"p@55w0rd!",
            "pm_addr":"192.0.2.209"
        }
        {
            "mac":[
                "gg:gg:gg:gg:gg:gg"
            ],
            "cpu":"4",
            "memory":"6144",
            "disk":"40",
            "arch":"x86_64",
            "pm_type":"pxe_ipmitool",
            "pm_user":"admin",
            "pm_password":"p@55w0rd!",
            "pm_addr":"192.0.2.210"
        }
    ]
}

After creating the template, save the file to the stack user’s home directory (/home/stack/instackenv.json). Initialize the stack user, then import instackenv.json into the director:

$ source ~/stackrc
$ openstack overcloud node import ~/instackenv.json

This imports the template and registers each node from the template into the director.

Assign the kernel and ramdisk images to each node:

$ openstack overcloud node configure <node>

The nodes are now registered and configured in the director.

After registering each node, you will need to inspect the hardware and tag the node into a specific profile. Profile tags match your nodes to flavors, and in turn the flavors are assigned to a deployment role.

To inspect and tag new nodes, follow these steps:

The addition of the profile option tags the nodes into each respective profiles.

Planning an overcloud deployment involves specifying how many nodes and which flavors to assign to each role. Like all Heat template parameters, these role specifications are declared in the parameter_defaults section of your custom environment file (in this case, /home/stack/templates/ceph-config from Chapter 3, Integrating with the Existing Ceph Cluster):

For this purpose, use the following parameters:

For example, to configure the overcloud to deploy three nodes for each role (Controller and Compute), add the following to your parameter_defaults:

parameter_defaults:
  ControllerCount: 3
  ComputeCount: 3
  OvercloudControlFlavor: control
  OvercloudComputeFlavor: compute

The creation of the overcloud requires additional arguments for the openstack overcloud deploy command. For example:

$ openstack overcloud deploy --templates \
  -e /usr/share/openstack-tripleo-heat-templates/environments/ceph-ansible/ceph-ansible-external.yaml \
  -e /home/stack/templates/ceph-config.yaml \
  -e --ntp-server pool.ntp.org \

The above command uses the following options:

$ openstack overcloud deploy \
  --answers-file /home/stack/templates/answers.yaml \
  --ntp-server pool.ntp.org

templates: /usr/share/openstack-tripleo-heat-templates/
environments:
  - /usr/share/openstack-tripleo-heat-templates/environments/ceph-ansible/ceph-ansible-external.yaml \
  - /home/stack/templates/ceph-config.yaml \

For a full list of options, run:

$ openstack help overcloud deploy

For more information, see Creating the Overcloud with the CLI Tools in the Director Installation and Usage guide.

The overcloud creation process begins and the director provisions your nodes. This process takes some time to complete. To view the status of the overcloud creation, open a separate terminal as the stack user and run:

$ source ~/stackrc
$ openstack stack list --nested

This configures the Overcloud to use your external Ceph Storage cluster. Note that you manage this cluster independently from the Overcloud. For example, you scale the Ceph Storage cluster using the Ceph management tools and not through the OpenStack Platform director.