Expanding the cluster

You can use the dashboard to expand the IBM Storage Ceph cluster for adding hosts, adding OSDs, and creating services such as Alertmanager, cephadm-exporter, CephFS-mirror, Grafana, ingress, MDS, node-exporter, Prometheus, RBD-mirror, and Ceph Object Gateway.

Once you bootstrap a new storage cluster, the Ceph Monitor and Ceph Manager daemons are created and the cluster is in HEALTH_WARN state. After creating all the services for the cluster on the dashboard, the health of the cluster changes from HEALTH_WARN to HEALTH_OK status.

Procedure

  1. Copy the admin key from the bootstrapped host to other hosts:

    Syntax 

    ssh-copy-id -f -i /etc/ceph/ceph.pub root@HOST_NAME

    Example 

    [ceph: root@host01 /]# ssh-copy-id -f -i /etc/ceph/ceph.pub root@host02
[ceph: root@host01 /]# ssh-copy-id -f -i /etc/ceph/ceph.pub root@host03

  2. Log in to the dashboard with the default credentials provided during bootstrap.

  3. Change the password and log in to the dashboard with the new password .

  4. On the landing page, click Expand Cluster.

  5. Add hosts:

    1. In the Add Hosts window, click +Add.

    2. Provide the hostname. This is same as the hostname that was provided while copying the key from the bootstrapped host.

      Note: You can use the tool tip in the Add Hosts dialog box for more details.

    3. Optional: Provide the respective IP address of the host.

    4. Optional: Select the labels for the hosts on which the services are going to be created.

    5. Click Add Host.

    6. Follow the above steps for all the hosts in the storage cluster.

  6. In the Add Hosts window, click Next.

  7. Create OSDs:

    1. In the Create OSDs window, for Primary devices, Click +Add.

    2. In the Primary Devices window, filter for the device and select the device.

    3. Click Add.

    4. Optional: In the Create OSDs window, if you have any shared devices such as WAL or DB devices, then add the devices.

    5. Optional: Click on the check-box Encryption to encrypt the features.

    6. In the Create OSDs window, click Next.

  8. Create services:

    1. In the Create Services window, click +Create.

    2. In the Create Service dialog box,

      1. Select the type of the service from the drop-down.

      2. Provide the service ID, a unique name of the service.

      3. Provide the placement by hosts or label.

      4. Select the hosts.

      5. Provide the number of daemons or services that need to be deployed.

    3. Click Create Service.

  9. In the Create Service window, Click Next.

  10. Review the Cluster Resources, Hosts by Services, Host Details. If you want to edit any parameter, click Back and follow the above steps.

  11. Click Expand Cluster.

  12. You get a notification that the cluster expansion was successful.

  13. The cluster health changes to HEALTH_OK status on the dashboard.

Verification

  1. Log in to the cephadm shell:

    Example 

    [root@host01 ~]# cephadm shell

  2. Run the ceph -s command.

    Example 

    [ceph: root@host01 /]# ceph -s

    The health of the cluster is HEALTH_OK.