On the node that you will use to host your quorum device, configure the quorum device with the following command. This command configures and starts the quorum device model net and configures the device to start on boot.

[root@qdevice:~]# pcs qdevice setup model net --enable --start
Quorum device 'net' initialized
quorum device enabled
Starting quorum device...
quorum device started

After configuring the quorum device, you can check its status. This should show that the corosync-qnetd daemon is running and, at this point, there are no clients connected to it. The --full command option provides detailed output.

[root@qdevice:~]# pcs qdevice status net --full
QNetd address:                  *:5403
TLS:                            Supported (client certificate required)
Connected clients:              0
Connected clusters:             0
Maximum send/receive size:      32768/32768 bytes

Enable the ports on the firewall needed by the pcsd daemon and the net quorum device by enabling the high-availability service on firewalld with following commands.

[root@qdevice:~]# firewall-cmd --permanent --add-service=high-availability
[root@qdevice:~]# firewall-cmd --add-service=high-availability

From one of the nodes in the existing cluster, authenticate user hacluster on the node that is hosting the quorum device. This allows pcs on the cluster to connect to pcs on the qdevice host, but does not allow pcs on the qdevice host to connect to pcs on the cluster.

[root@node1:~] # pcs host auth qdevice
Username: hacluster
Password:
qdevice: Authorized

Add the quorum device to the cluster.

Before adding the quorum device, you can check the current configuration and status for the quorum device for later comparison. The output for these commands indicates that the cluster is not yet using a quorum device, and the Qdevice membership status for each node is NR (Not Registered).

[root@node1:~]# pcs quorum config
Options:

[root@node1:~]# pcs quorum status
Quorum information
------------------
Date:             Wed Jun 29 13:15:36 2016
Quorum provider:  corosync_votequorum
Nodes:            2
Node ID:          1
Ring ID:          1/8272
Quorate:          Yes

Votequorum information
----------------------
Expected votes:   2
Highest expected: 2
Total votes:      2
Quorum:           1
Flags:            2Node Quorate

Membership information
----------------------
    Nodeid      Votes    Qdevice Name
         1          1         NR node1 (local)
         2          1         NR node2

The following command adds the quorum device that you have previously created to the cluster. You cannot use more than one quorum device in a cluster at the same time. However, one quorum device can be used by several clusters at the same time. This example command configures the quorum device to use the ffsplit algorithm. For information on the configuration options for the quorum device, see the corosync-qdevice(8) man page.

[root@node1:~]# pcs quorum device add model net host=qdevice algorithm=ffsplit
Setting up qdevice certificates on nodes...
node2: Succeeded
node1: Succeeded
Enabling corosync-qdevice...
node1: corosync-qdevice enabled
node2: corosync-qdevice enabled
Sending updated corosync.conf to nodes...
node1: Succeeded
node2: Succeeded
Corosync configuration reloaded
Starting corosync-qdevice...
node1: corosync-qdevice started
node2: corosync-qdevice started

Check the configuration status of the quorum device.

From the cluster side, you can execute the following commands to see how the configuration has changed.

The pcs quorum config shows the quorum device that has been configured.

[root@node1:~]# pcs quorum config
Options:
Device:
  Model: net
    algorithm: ffsplit
    host: qdevice

The pcs quorum status command shows the quorum runtime status, indicating that the quorum device is in use. The meanings of of the Qdevice membership information status values for each cluster node are as follows: