6.2. Hosts Operations

Procedure 6.1. To Add a Host

1. Click the Hosts tab to list available hosts.
2. Click New to open the New Host window.
   

   Figure 6.2. New Host Window

3. Select the Host Cluster for the new host from the drop-down menu.

   Table 6.2. Add Hosts Properties

   Field	Description
   Host Cluster	The cluster to which the host belongs.
   Name	The name of the host. This text field has a 40-character limit and must be a unique name with any combination of uppercase and lowercase letters, numbers, hyphens, and underscores. If Nagios is enabled, the host name given in Name field of Add Host window should match the host name given while configuring Nagios.
   Address	The IP address or resolvable hostname of the host.
   Root Password	The password of the host's root user. This can only be given when you add the host, it cannot be edited afterwards.
   SSH Public Key	Copy the contents in the text box to the /root/.ssh/authorized_keys file on the host if you'd like to use the Manager's ssh key instead of using a password to authenticate with the host.
   Automatically configure host firewall	When adding a new host, the Manager can open the required ports on the host's firewall. This is enabled by default. This is an Advanced Parameter. The required ports are opened if this option is selected.
   SSH Fingerprint	You can fetch the host's ssh fingerprint, and compare it with the fingerprint you expect the host to return, ensuring that they match. This is an Advanced Parameter.

   Note

   For Red Hat Enterprise Linux 7 hosts, iptables-service is used to manage firewall and existing firewalld configurations will not be enforced if "Automatically configure host firewall is chosen."
4. Enter the Name, and Address of the new host.
5. Select an authentication method to use with the host:
   1. Enter the root user's password to use password authentication.
   2. Copy the key displayed in the SSH PublicKey field to /root/.ssh/authorized_keys on the host to use public key authentication.
6. The mandatory steps for adding a Red Hat Gluster Storage host are complete. Click Advanced Parameters to show the advanced host settings:
   1. Optionally disable automatic firewall configuration.
   2. Optionally disable use of JSON protocol.

      Note

      With Red Hat Gluster Storage Console, the communication model between the engine and VDSM now uses JSON protocol, which reduces parsing time. As a result, the communication message format has changed from XML format to JSON format. Web requests have changed from synchronous HTTP requests to asynchronous TCP requests.
   3. Optionally add a host SSH fingerprint to increase security. You can add it manually, or fetch it automatically.
7. Click OK to add the host and close the window.
   The new host displays in the list of hosts with a status of "Installing" and then it goes to "Initialization" state and the host comes up.

   Note

   The host will be in Up status after the status of "Installing" and "Initialization" state. The host will have Non-Operational status when the host is not compatible with the cluster compatibility version. The Non-Responsive status will be displayed if the host is down or is unreachable.
   You can view the progress of the host installation in the Details pane.

Procedure 6.2. To Activate a Host

1. In the Hosts tab, select the host you want to activate.
2. Click Activate. The host status changes to Up.

Procedure 6.5. To Import a Host to a Cluster

1. Click the Cluster tab and select a cluster to display the General tab with details of the cluster.
2. In Action Items, click Import to display the Add Hosts window.
   

   Figure 6.5. Add Hosts Window

3. Enter the Name and Root Password. Select Use a common password if you want to use the same password for all hosts.
4. Click Apply.
5. Click OK to add the host to the cluster.

Procedure 6.6. To Detach a Host from a Cluster

1. Click the Cluster tab and select a cluster to display the General tab with details of the cluster.
2. In Action Items, click Detach to display the Detach Hosts window.
3. Select the host you want to detach and click OK. Select Force Detach if you want to perform force removal of the host from the cluster.

Procedure 6.7. To Delete a Host

1. Click the Hosts tab to display a list of hosts. Select the host you want to remove. If the required host is not visible, perform a search.
2. Click Maintenance to place the host into maintenance. Click OK to confirm the action. The Status field of the host changes to Preparing for Maintenance, followed by Maintenance. The icon changes to indicate that the host is in maintenance mode.

   Important

   If you move the Hosts under Maintenance mode, it stops all gluster process such as brick, self-heal, and geo-replication. If you wish to reuse this host, ensure to remove the gluster related information stored in /var/lib/glusterd manually.
3. Click Remove.
4. Click OK to confirm.

Procedure 6.8. Creating Bricks

1. Click the Hosts tab to display a list of hosts.
2. Select a host and select the Storage Devices sub-tab. The list of storage devices is displayed.
3. Select a storage device from the list and click Create Brick. The Create Brick page is displayed..
4. Enter the Brick Name, Mount Point name, and the No. of Physical Disks in RAID Volume.
   The Mount Point is auto-suggested and can be edited.
5. Confirm the Raid Type.
6. Click OK. A new thinly provisioned logical volume is created with recommended Red Hat Gluster Storage configurations using the selected storage devices. This Logical Volume will be mounted at the specified mount point and this mount point can be used as brick in gluster volume.