Virtual Machines Overview and Usage

This guide explains how virtualization works within Cozystack.

Virtualization Packages

The Cozystack catalog includes three packages related to virtualization:

• virtual-machine - Virtual Machine (simple)
• vm-disk - Virtual Machine disk
• vm-instance - Virtual Machine instance

Virtual Machine (simple)

This package provides a quick way to create a simple virtual machine. It allows you to specify the bare minimum parameters to run a VM, but it only supports a single-disk virtual machine.

For production workloads, it is recommended to use vm-disk and vm-instance instead.

Virtual Machine Disk

Before creating a Virtual Machine instance, you need to create a disk from which the VM will boot.

This package defines a virtual machine disk used to store data. You can download an image to the disk via HTTP or upload it from a local image. You can also create an empty image.

1. HTTP:

   source:
     http:
       url: "https://download.cirros-cloud.net/0.6.2/cirros-0.6.2-x86_64-disk.img"
   

2. Upload:

   source:
     upload: {}
   

   After the disk is created, it will generate a command for uploading using the virtctl tool.

   Note:

   If you want to let virtctl know about right endpoint for uploading images, you need to configure a cluster to specify an endpoint for it:

   1. Modify your ingress application to enable cni-uploadproxy option.

      kubectl patch -n tenant-root ingresses.apps.cozystack.io ingress --type=merge -p '{"spec":{
        "cdiUploadProxy": true
      }}'
      

   2. Modify your cozystack config to provide a valid CDI uploadproxy endpoint:

   values-cdi: |
     uploadProxyURL: https://cdi-uploadproxy.example.org  
   

3. Empty:

   source: {}
   

Optionally, you can specify that the disk is an optical CD-ROM:

optical: true

Created disks can be attached to a Virtual Machine instance.

Virtual Machine Instance

This package defines a Virtual Machine instance, which requires specifying the previously created vm-disk. The first disk is always bootable, and the VM will attempt to boot from it.

disks:
- name: example-system
- name: example-data

The rest parameters are similar to Virtual Machine (simple)

Accessing Virtual Machines

You can access the virtual machine using the virtctl tool:

• KubeVirt User Guide - Virtctl Client Tool

To access the serial console:

virtctl console <vm>

To access the VM using VNC:

virtctl vnc <vm>

To SSH into the VM:

virtctl ssh <user>@<vm>