How to start a Public Cloud instance on a bootable volume
Learn how to start an instance on an attached volume.
Public Cloud instances come with an original disk that is copied from a system image (Debian 12, Windows Server, etc.). It is also possible to use additional volumes, which are persistent disks that will allow data to be stored.
You can also deploy an operating system to and from a volume. The Public Cloud instance will then start on this volume instead of the original disk.
OpenStack natively allows you to boot from a volume. It involves making the volume bootable and starting the instance from this volume. The changes will cause the original disk to be replaced by the new volume. The functionality described in this guide eliminates the need to access the original disk and, therefore, takes advantage of the volume.
NOTE: With the current version of OpenStack, rescue-pro mode is not available on an instance booted via a bootable volume.
Requirements
Instructions
Creating a bootable volume from an image
Log in to the Horizon interface.
Select the appropriate region from the drop-down menu at the top left.
On the Project tab, open the Volumes section and click the Volumes dashboard.
Click on Create Volume.
In the dialog box that opens, enter or select the following values:
- Volume Name
- Description (optional)
- Volume Source: Image
- Use image as a source
- Type
- Size (GB)
- Availability Zone: nova
Click on Create Volume.
The volume will be in a creating state then a downloading state before being available.
If you click the volume name, you will see the volume's details and that the Bootable line says Yes.
Starting an instance using a bootable volume
Log in to the Horizon interface.
Select the appropriate region from the drop-down menu at the top left.
On the Project tab, open the Compute section and choose Instances.
Click on Launch Instance.
In the Launch Instance dialog box, enter the information requested. Refer to the guide Create an instance from the Horizon interface for more details.
In the Source tab, choose Volume in the Select Boot Source field.
A new field for volume selection appears. You can select the previously created volume from the list.
Make your selections in the Details, Flavor, and Networks areas. Click on Launch Instance.
The instance will be in a build state then Block Device Mapping state before being available.
The instance will eventually have the volume attached.
Go further
Browse all the Compute guides.
Browse the rest of the OVHcloud US documentation for guides on our other products and services.
Learn more about Public Cloud Compute on the OVHcloud US website.