[Thincrust-devel] issues with zip packaging for appliances

[Bryan Kearney]

Perry Myers wrote:
> I've been playing with the -p zip option to appliance-creator and ran 
> into an issue that I'm not sure how we can solve...
> 
> If the output format of a disk image is raw there are two sizes, the 
> logical size and the actual size.  So if I create a 20GB disk partition 
> in the kickstart, but only use 1.5 GB the file appears to be 20GB but 
> actually only takes 1.5GB on disk.

Why the disparity? Could you split it into 2 disks (system and data) and 
provide instructions on growing hte data disk?

> 
> When appliance-creator attempts to add this disk image to the zip 
> archive it fails because the logical size of the file is > 4GB which is 
> the limitation of an individual file in a zip archive.  You can pass the 
> allowZip64=True parameter to Zip in python to allow the zip64 extensions 
> to remove this limitation, but then the zip file can no longer be 
> extracted using the standard unzip command line tools (also not sure if 
> native Windows zip can handle this)
> 
> It will probably be fairly common that appliance images will have 
> logical sizes of > 4GB, so zip files are really only useful for 
> packaging appliances if the image is qcow compressed instead of raw.  If 
> the images are qcow, then the logical=actual and will generally be < 4GB.
> 
> We can consider using another archiving format like tar, but then we 
> can't  extract appliances on Windows with the default tools there.  We 
> can force qcow compression for zip packaging but that limits our 
> hypervisor usage.


Are you sure that tar does not work on Windows? I tend to remember it 
does. I have it in a VM at home and can try later tonite.

-- bk