Creating an instance#

A Virtual Machine (VM) running in the cloud is commonly referred to as an instance.

Note

By default instances in OpenNebula are not persistent, or “ephemeral”. This means that the machines disk will persist between reboots or shutdowns, but when the instance is terminated the disk is deleted and the data is gone.

Step by step guide#

  • Once you have logged in to OpenNebula you will be presented with the dashboard.

The dashboard#

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From here you can click on the green plus to go straight to the VM creation screen or the blue list button to view the VM’s screen which displays all of your currently running instances.

The VM’s screen#

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  • When you click on the green plus button you are presented with the “create virtual machine” menu.

  • From here you will need to chose from one of the available VM templates to get started.

Note

Each template should describe which operating system and version the virtual machine has installed. It might also contain some extra information such as whether the machine has a graphical desktop installed, and whether the machine uses VNC or SPICE protocol for accesing a screen.

Customising your instance#

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  • Once you have selected the template you want to use some more options will appear below.

  • You can customise the following options: * The name of your VM * How many instances of your VM you would like to create * How much RAM to give each instance * How big you would like the disk to be * How many CPU’s to give each instance and how many virtual CPU’s this will be divided into in the guest virtual machine.

Note

For example: 2 CPU’s will assign to 2 cores of the virtual host to the guest machine. 2 CVPU means that the virtual machine will see this as 2 virtual cores. 2 CPU and 1 VCPU would mean the VM will be assigned 2 cores of the host machine but the VM will only see this as 1 larger CPU

  • It is recommended that you don’t click on the toggle to “instantiate as persistent” unless necessary. This will create a whole new image on the OpenNebula storage and this can start to get very expensive with regard to storage usage.

  • All of these options can be left at their default values if you choose.

Warning

Keep in mind that you will not be able to exceed your quotas for CPU, RAM etc. Only give your instances the resource they need to function. You can always add more if you need it later.

  • If you want to connect your VM to a Virtual Network Click on the drop-down in the bottom list that says “network”. This will open up the network menu where you can create network interfaces for your VM and assign the interfaces to virtual networks.

Network menu#

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  • To add a network interface click on the blue “+ Network Interface” button

  • Select the network you want this interface to connect to

  • In the “Force IPv4” field you can provide a specific IPv4 address you would like the machine to have. * OpenNebula will only be able to assign this IP to your instance if it is available (not taken already and within the valid IP range) on the Virtual Network you have chosen.

  • You can repeat this process and add multiple interfaces / networks to the VM

  • Once you have finished customising your VM you can click the green “Create” button which is at the top of the page

  • You will now be taken back to the VM’s view and your new VM instances should be listed. They will need a short amount of time to instantiate and boot up. Once the machine is ready its status should be displayed as “RUNNING”.

The VM’s screen with the new instance#

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  • Use the grey refresh button to update the information being displayed

Your VM is now ready for use