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Ruben S. Montero edited this page Jun 27, 2023 · 14 revisions

Single Front-end & Shared Storage

This scenario is a variation of the local storage setup. Here, the storage for virtual machines (VMs) and the image repository are provided by a NFS/NAS server. Running VMs directly from shared storage can enhance the fault tolerance of the system in the event of a host failure, although it comes with the drawback of increased I/O latency.

⚠️ Note: The playbook assumes that you have already configured and mounted the NFS shares in all the servers.

Storage

NFS server configuration

The NFS/NAS server is configured to export the datastore folders to the hosts in the OpenNebula cloud. In this example we assume that the following structure is created in the NFS/NAS sever:

root@nfs-server:/# ls -ln /srv
total 0
drwxr-xr-x 2 9869 9689 6 Jun 26 17:55 0
drwxr-xr-x 2 9869 9689 6 Jun 26 17:55 1
drwxr-xr-x 2 9869 9689 6 Jun 26 17:55 2

:important: Note: The ownership of the folders MUST be 9869 as this is the UID/GID assigned to the oneadmin account during the installation.

:important: Note: The files & kernels datastore (folder /srv/2, in the example) will be only mounted in the front-end; hosts will always use local storage for this datastore.

This folder is exported to the OpenNebula servers, for example:

# /etc/exports
#
# See exports(5) for more information.
#
# Use exportfs -r to reread
# /export	192.168.1.10(rw,no_root_squash)
/srv 172.20.0.0/24(rw,soft,intr,async,rsize=32768, wsize=32768)

NFS client configuration

In this example all servers (front-end and hosts) mounts the NFS shared under the /mnt folder:

root@ubuntu2204-17:/# ls -la /mnt/
total 4
drwxr-xr-x  5 root root   33 Jun 26 15:58 .
drwxr-xr-x 18 root root 4096 Jun 27 09:30 ..
drwxr-xr-x  2 9869 9689    6 Jun 26 15:55 0
drwxr-xr-x  2 9869 9689    6 Jun 26 15:55 1
drwxr-xr-x  2 9869 9689    6 Jun 26 15:55 2

Inventory

The following snippet shows the configuration required to use the shared storage using the above mount points:

ds:
  mode: shared
  mounts:
  - type: system
    path: /mnt/0
  - type: image
    path: /mnt/1
  - type: files
    path: /mnt/2

⚠️ Note: files (/mnt/2) will only be symlinked in the front-end

Networking

To configure the network you can follow the local storage scenario section.

OpenNebula Front-end & Services

To configure the front-end services or using your enterprise edition token you can follow the local storage scenario sections.

The complete inventory file

The following file show the complete settings to install a single front-end with two hosts using local storage:

---
all:
  vars:
    ansible_user: root
    one_version: '6.6'
    one_pass: opennebulapass
    ds:
      mode: shared
      mounts:
      - type: system
        path: /mnt/0
      - type: image
        path: /mnt/1
      - type: files
        path: /mnt/2
    vn:
      admin_net:
        managed: true
        template:
          VN_MAD: bridge
          PHYDEV: eth0
          BRIDGE: br0
          AR:
            TYPE: IP4
            IP: 172.20.0.100
            SIZE: 48
          NETWORK_ADDRESS: 172.20.0.0
          NETWORK_MASK: 255.255.255.0
          GATEWAY: 172.20.0.1
          DNS: 1.1.1.1

frontend:
  hosts:
    f1: { ansible_host: 172.20.0.6 }

node:
  hosts:
    n1: { ansible_host: 172.20.0.7 }
    n2: { ansible_host: 172.20.0.8 }

Running the Ansible Playbook

  • 1. Prepare the inventory file: Update the local.yml file in the inventory file to match your infrastructure settings. Please be sure to update or review the following variables:

    • ansible_user, update it if different from root.
    • one_pass, change it to the password for the oneadmin account
    • one_version, be sure to use the latest stable version here

  • 2. Check the connection: Verify the network connection, ssh and sudo configuration run the following command:

ansible -i inventory/local.yml all -m ping -b
  • 3. Site installation: Now we can run the site playbook that install and configure OpenNebula services
ansible-playbook -i inventory/local.yml opennebula.deploy.main

Verifying the Installation

Now that the OpenNebula cloud is installed and ready to use let's review your installation. Let's first check the hosts, ssh into the frontend and check the hosts registered in OpenNebula:

# sudo -i -u oneadmin
$ onehost list

In the same way you can check the datastores and virtual networks

$ onedatastore list

$ onevnet list

Finally let's create a simple VM. Let's download an alpine image from the OpenNebula MarketPlace:

$ onemarketapp export

And instantiate the template attached to the admin_net network:

$ onetemplate instantiate

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