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

[Christy Perez]

On Wed, 2014-07-02 at 10:40 +0800, Royce Lv wrote:
> On 2014年07月02日 04:07, Christy Perez wrote:
> >
> >
> > On Tue, 2014-07-01 at 15:53 +0800, 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.
> >>       (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.
> >>
> > this might be something for down the line, but some distros (not sure
> > which, other than Ubuntu) or even private organizations, keep image
> > files online too. So we might want to think about allowing remote images
> > to be used. This would have to be different than the remote template
> > logic, of course, since we would want to pull the image down into a
> > storage pool and then use it locally.
> >
> > Scroll to the bottom: http://cloud-images.ubuntu.com/precise/current/
> > http://cloud-images.ubuntu.com/
> Thanks Christy!
> 
> That is exactly what I want for this feature.Together with what I posted 
> in RFC "Upload and download image for OOTB storage pool".
> The whole flow of this scenario will be:
> 1. download a cloud image to ISO storage pool.
> 2. create a template from this cloud image.
> 3. create a vm from this template.
I think I may have misunderstood the OOTB storage pool a bit then. I'll
have to re-read those e-mails more carefully.
> 
> I agree with you that this is different from the remote template logic, 
> because this image is the base image of other vms. And other vms' image 
> file is cow image of this base.
> If this base image locates remotely, I'm afraid this will be an IO 
> bottleneck of the VM. This is different with ISO streaming, because ISO 
> is only used one time when installation, but this base image file will 
> be used every time read occurs.
I was thinking we'd pull it down and use the local one going forward,
after making a template from it. Re-reading what I wrote, I didn't make
that very clear. 
> >
> >> _______________________________________________
> >> Kimchi-devel mailing list
> >> Kimchi-devel at ovirt.org
> >> http://lists.ovirt.org/mailman/listinfo/kimchi-devel
> >>
> > Regards,
> >
> > - Christy
> >
> >
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> >
>