Re: [Libguestfs] Appliance image. Why raw?

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#L2... >>>> >>>> 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.