[Libguestfs] Appliance image. Why raw?

[Richard W.M. Jones]

On Tue, Jun 20, 2017 at 06:48:16PM +0300, Pavel Butsykin wrote:
> On 20.06.2017 18:41, Richard W.M. Jones wrote:
> >On Tue, Jun 20, 2017 at 06:34:28PM +0300, Pavel Butsykin wrote:
> >>On 20.06.2017 17:47, Richard W.M. Jones wrote:
> >>>On Tue, Jun 20, 2017 at 05:04:53PM +0300, Pavel Butsykin wrote:
> >>>>I noticed that raw is intentionally used as image format for appliance
> >>>>image. So I would like to ask, is there any reason to use raw as image
> >>>>format for appliance?
> >>>
> >>>The simple answer is because we create the appliance image (it's an
> >>>ext2/3/4 filesystem) using e2fsprogs, and that library wouldn't know
> >>>how to create anything else since it always assumes it's writing
> >>>directly to a device.
> >>>
> >>>https://github.com/libguestfs/supermin/blob/master/src/format_ext2.mli#L22-L29
> >>>
> >>>HTH,
> >>
> >>Yes, the main point is clear, thanks.
> >>
> >>I asked because we supply the prepared appliance, so would like to use
> >>qcow2. Given that the applaince image is completely controlled, for
> >>supermin and fixed appliance, in both the cases. We could use
> >>autodetect, it is already implemented in qemu, so to add it to
> >>libguestfs will simply. I'm going to prepare the patches, what do you
> >>think?
> >
> >./configure-time option? >
> >Autodetection is actually not insecure with modern qemu, but people
> >still think it is ...
> 
> Yes, but in our case it will be safe, because we have full control over
> appliance image.

As long as a configure time option will work for you, I'd
prefer to do that.

Rich.

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