Chapter 9. Managing hosts on the Ceph dashboard

Procedure

1. From the dashboard navigation, go to Cluster→Hosts.

2. Select the host to enter maintenance mode, and click Enter Maintenance from the action drop-down.

   Note

   If the host contains Ceph Object Gateway (RGW) daemons, a warning displays that removing RGW daemons can cause clients to lose connectivity. Click Continue to enter maintenance.

   Note

   When a host enters maintenance mode, all daemons are stopped. Check the status of the daemons of a host by expanding the host view and switching to the Daemons tab.

   A notification displays that the host was moved to maintance successfully.

Verification

1. The maintenance label displays in the Status column of the Host table.

   Note

   If the maintenance mode fails, a notification displays, indicating the reasons for failure.

Procedure

1. From the dashboard navigation, go to Cluster→Hosts.

2. Select the host currently in maintenance mode, and click Exit Maintenance from the action drop-down.

   Note

   Identify which host is maintenance by checking for the maintenance label in the Status column of the Host table.

   A notification displays that the host was moved out of maintenance successfully.

3. Create the required services on the host. By default, crash and node-exporter get deployed.

Verification

1. The maintenance label is removed from the Status column of the Host table.

Procedure

1. From the dashboard navigation, go to Cluster→Hosts.

2. Select the host that is to be removed, and click Start Drain from the action drop-down.

   Figure 9.1. Selecting Start Drain option

   

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   This option drains all the daemons from the host.

   Note

   The _no_schedule label is automatically applied to the host, which blocks the deployment of daemons on this host.

   1. Optional: To stop the draining of daemons from the host, click Stop Drain from the action drop-down.

3. Check that all the daemons are removed from the host.

   1. Expand the host row.

   2. Go to the Daemons tab.

      No daemons should be listed.

      Important

      A host can be safely removed from the cluster after all the daemons are removed from it.

4. Select the host that is to be removed, and click Remove from the action drop-down.

   1. In the Remove Host notification, select Yes, I am sure and click Remove Host.

      

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      A notification displays that the host is removed successfully.