An image is an exact copy of the volume’s file system and its contents. You can create boot volumes from images and then deploy cloud servers (virtual machines) from them.
You can use two types of images to create a cloud server:
- Prebuilt. These are preconfigured images for the Cloud platform. For each of them, the operational environment was prepared, the necessary parameters were configured, and the assembly was performed. The list of available prebuilt images can be viewed in the Control panel when creating a cloud server in the Source field or using the OpenStack utilities;
- Own images. If you need an image that is not presented in the list of prebuilt images, you can upload your own image in the ami, ari, aki, iso, raw, qcow2, vdi, vhd, vhdx, or vmdk format. You can also create an image of the existing server’s volume, more information can be found below.
You can create an image from the server’s local or network volume. Such images are copies of the volumes, so if the OS and some software are installed on the cloud server, then you can deploy an already configured cloud server from the image.
Examples of cases in which it is convenient to create a server from a volume image:
- quick setup of servers of the same type or cloning servers — you can create a volume image from the existing server with the necessary settings, and then deploy identical virtual machines from it. This is faster than configuring multiple servers in a row;
- relocating the server to other pools, projects, or accounts — to do this, you need to create an image from the virtual machine volume, save it to your local computer, and then deploy a server from this image;
- if the image that the server was previously created from was deleted, you can create an image from the server volume and, if necessary, deploy the same cloud server.