On Mon, May 28, 2018 at 08:38:33PM +0200, Kevin Wolf wrote: > Just accessing the image file within a tar archive is possible and we > could write a block driver for that (I actually think we should do > this), but it restricts you because certain operations like resizing > aren't really possible in tar. Unfortunately, resizing is a really > common operation for non-raw image formats.
We do this already in virt-v2v (using file.offset and file.size parameters in the raw driver). For virt-v2v we only need to read the source so resizing isn't an issue. For most of the cases we're talking about the downloaded image would also be a template / base image, so I suppose only reading would be required too. I also wrote an nbdkit tar file driver (supports writes, but not resizing). https://manpages.debian.org/testing/nbdkit-plugin-perl/nbdkit-tar-plugin.1.en.html Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com Fedora Windows cross-compiler. Compile Windows programs, test, and build Windows installers. Over 100 libraries supported. http://fedoraproject.org/wiki/MinGW
