Volumes

Volumes are block storage devices that you attach to instances to enable persistent storage. You can attach a volume to a running instance or detach a volume and attach it to another instance at any time. You can also create a snapshot and backups from volumes.

Volumes can also be used to create new images.

Boot volumes

When creating an instance from an image, a boot volume is automatically created and the image is copied to the volume. Unless the option is selected at instance creation time, this volume will not be automatically deleted when the VM is destroyed.

The volume must be deleted in the Volume>Volume menu to reclaim quota. Conversely, a volume cannot be deleted as long as it is attached to a VM.

Once a volume is no longer attached to a VM (its changes from in-use to available) it can be used as a boot volume for a new VM. Select Launch as instance in the actions menu of the volume.

Snapshots and backups

Snapshots and backups allow you to restore the content of a volume to a previous state. Since they are stored within the same Ceph filesystem as the volumes, they can be created and restored very quickly. However, this also means that they in case of a catastrophic failure such as a loss of the Ceph cluster, they would be lost as well. Any critical data should therefore be backed up outside of TGCC cloud by a dedicated and application specific backup solution.

Snapshots are tied to the volume they were created from. It is not possible to delete a volume as long as it has snapshots. They can be used to create images and boot volumes.

Backups are independent of the volume they were created from. However they must be restored to a new volume before they can be used further.