Chapter 6. Basic Operations

Some basic operations are required for many administrative and troubleshooting tasks. This section covers how to safely perform basic tasks like shutting down and starting up the hyperconverged cluster.

6.1. Creating a shutdown playbook

A hyperconverged environment must be shut down in a particular order. The simplest way to do this is to create a shutdown playbook that can be run from the Hosted Engine virtual machine.

The ovirt.ovirt.shutdown_env role enables Global Maintenance Mode, and initiates shutdown for all virtual machines and hosts in the cluster. Host shutdown is asynchronous. The playbook terminates before hyperconverged hosts are actually shut down.

Prerequisites

  • Ensure that the ovirt.ovirt.shutdown_env ansible role is available on the Hosted Engine virtual machine. 

    # yum install ovirt-ansible-shutdown-env -y

Procedure

  1. Log in to the Hosted Engine virtual machine.

  2. Create a shutdown playbook for your environment.

    Use the following template to create the playbook file.

    • Replace ovirt-engine.example.com with the FQDN of your Hosted Engine virtual machine.
    • Replace 123456 with the password for the admin@internal account.

    Example playbook file: shutdown_rhhi-v.yml

    ---
- name: oVirt shutdown environment
  hosts: localhost
  connection: local
  gather_facts: false

  vars:
    engine_url: https://ovirt-engine.example.com/ovirt-engine/api
    engine_user: admin@internal
    engine_password: 123456
    engine_cafile: /etc/pki/ovirt-engine/ca.pem

  roles:
    - ovirt.ovirt.shutdown_env

6.2. Shutting down RHHI for Virtualization

A hyperconverged environment must be shut down in a particular order. Use an Ansible playbook to automate this process and ensure that your environment is shut down safely.

Prerequisites

  • Create a shutdown playbook as described in Creating a shutdown playbook

  • Ensure that the ovirt.ovirt.shutdown_env ansible role is available on the Hosted Engine virtual machine. 

    # yum install ovirt-ansible-shutdown-env -y

Procedure

  1. Run the shutdown playbook against the Hosted Engine virtual machine. 

    # ansible-playbook -i localhost <shutdown_rhhi-v.yml>

6.3. Starting up a hyperconverged cluster

Starting up a hyperconverged cluster is more complex than starting up a traditional compute or storage cluster. Follow these instructions to start up your hyperconverged cluster safely.

  1. Power on all hosts in the cluster.

  2. Ensure that the required services are available.

    1. Verify that the glusterd service started correctly on all hosts. 

      # systemctl status glusterd
● glusterd.service - GlusterFS, a clustered file-system server
   Loaded: loaded (/usr/lib/systemd/system/glusterd.service; enabled; vendor preset: disabled)
  Drop-In: /etc/systemd/system/glusterd.service.d
           └─99-cpu.conf
   Active: active (running) since Wed 2018-07-18 11:15:03 IST; 3min 48s ago
   [...]

      If glusterd is not started, start it. 

      # systemctl start glusterd

    2. Verify that host networks are available and hosts have IP addresses assigned to the required interfaces. 

      # ip addr show

    3. Verify that all hosts are part of the storage cluster (listed as Peer in Cluster (Connected)). 

      # gluster peer status

Number of Peers: 2

Hostname: 10.70.37.101
Uuid: 773f1140-68f7-4861-a996-b1ba97586257
State: Peer in Cluster (Connected)

Hostname: 10.70.37.102
Uuid: fc4e7339-9a09-4a44-aa91-64dde2fe8d15
State: Peer in Cluster (Connected)

    4. Verify that all bricks are shown as online. 

      # gluster volume status engine
Status of volume: engine
Gluster process                             TCP Port  RDMA Port  Online  Pid
------------------------------------------------------------------------------
Brick 10.70.37.28:/gluster_bricks/engine/en
gine                                        49153     0          Y       23160
Brick 10.70.37.29:/gluster_bricks/engine/en
gine                                        49160     0          Y       12392
Brick 10.70.37.30:/gluster_bricks/engine/en
gine                                        49157     0          Y       15200
Self-heal Daemon on localhost               N/A       N/A        Y       23008
Self-heal Daemon on 10.70.37.30             N/A       N/A        Y       10905
Self-heal Daemon on 10.70.37.29             N/A       N/A        Y       13568

Task Status of Volume engine
------------------------------------------------------------------------------
There are no active volume tasks

  3. Start the hosted engine virtual machine.

    1. Run the following command on the host that you want to be the hosted engine node. 

      # hosted-engine --vm-start

    2. Verify that the hosted engine virtual machine has started correctly. 

      # hosted-engine --vm-status

  4. Take the hosted engine virtual machine out of Global Maintenance mode.

    1. Log in to the Administration Portal.
    2. Click Compute → Hosts and select the hosted engine node.
    3. Click ⋮ → Disable Global HA Maintenance.

  5. Start any other virtual machines using the Web Console.

    1. Click Compute → Virtualization.
    2. Select any virtual machines you want to start and click Run.