[Thincrust-devel] issues with zip packaging for appliances

[Alan Pevec]

Perry Myers wrote:
> for the oVirt Appliance, if we have the output format as raw the image 
> size is 1.5GB since it is sparse
> 
> with the output format as qcow2 the image only drops to 1.2GB
> 
> if I take that qcow2 image and put it in a zip file the resulting zip 
> file is around 400MB
> 
> if I zip the raw 1.5GB image it's also around 400MB (maybe a little bit 
> more but not much)  This only worked with the Zip64 extensions turned on 
> though
> 
> So for distribution of appliances qcow2 does not really get you any 
> savings.  You'd still have to use a compressed package format.  We've 
> been doing that up until now by putting the image into an RPM which 
> compresses it.

We could compressed the image file individually by e.g. gzip/bzip and then package it into zip archive.
virt-image tool would then detect compression and expand the image during the installation.
Is there virt-image for windows? For this plan to work on windows, virt-image would need to be embedded inside the appliance archive.

> So the fundamental question here is... what packaging format can we use that will have good compression, is natively supported on a wide variety of platforms (Unix, Windows, Linux) and will hold raw images that are fairly large. 

7-zip.org looks promising but again that's not installed on windoze by default