[Kimchi-devel] [RFC]Create VM from image

[Aline Manera]

On 07/01/2014 04:53 AM, Royce Lv wrote:
> Currently kimchi just support create a vm from an ISO defined 
> template. This requires duplicate installation.
> This release we want to support create a vm from an installed image.
>
> This involves the following change:
>
> 1. Create a template from an image:
>
> POST /templates/template-1
>     {'base': 'abs_base_img_path'}
>
> Implementation:
>     (1)probe image os distro and version to get suggested config.
>     (2)Avoid image to be deleted.
>     (3)Avoid using ISO and base image at the same time.
>
> 2. Create a vm from image based template:
>     This part has already been covered by Aline's prototype patch.
>
>     POST /vms/vm-1
>         {'storagepool': 'default', 'network': 'default', 
> 'disks':[{'index':0, 'base': 'abs_path'}]}
>     or
>         {'storagepool': 'default', 'network': 'default', 
> 'disks':[{'index':0, 'base': 'abs_path', 'volume': 'scsi_volume'}]}
>
>     The create vm implementation need to be re-considered for the 
> following points:
>     (1) when creating vm on scsi/iscsi pool, if volume size smaller 
> than original image, need to be rejected.

 From that, I assume you will copy the img content to the scsi/iscsi 
volume. Is that correct?
If so, can't we use backing store 
(http://libvirt.org/formatstorage.html#StorageVolBacking) for the 
existing img and make the vm volume the RW img?

During my prototype development, I used backing store and it worked well 
with directory storage volumes
But I haven't tested it with scsi/iscsi volumes

>     (2) when creating vm on directory based pool, volume generating 
> logic is different with allocation new volume.
>     (2) xml generating need to be refactored.
>
> Anything else need to be considered, welcome your comments.