Re: [Qemu-devel] [PATCH 1/5] RFC: Efficient VM backup for qemu (v1)

[Stefan Hajnoczi]

On Thu, Nov 22, 2012 at 7:05 PM, Dietmar Maurer <address@hidden> wrote:
>> QEMU's implementation has partial support for Stream-Optimized
>> Compressed images.  If you complete the code for this subformat, not only
>> does this benefit the VM Backup feature, but it also makes qemu-img convert
>> more powerful for everyone.  I hope we can kill two birds with one stone
>
> The doc contain the following link:
>
> http://www.vmware.com/download/patents.html
>
> I simply have no idea how to check all those patents. How can someone tell
> that they do not cover things in the specs? I am really curios?

If you want to investigate it then you would look at each one or use
search engines to make it easier (skip all the non-disk image related
patents).

But keep in mind that any other company out there could have a patent
on out-of-order data in an image file or other aspects of what you're
proposing.  Reinventing the wheel may not stop you from infringing on
their patents so the fact that VMware may or may not have patents
doesn't change things if you're really trying to find possible issues.

This is why SQLite has a policy of only using algorithms that are
older than 17 years, see comment by drh:
http://www.sqlite.org/cvstrac/wiki?p=BlueSky

Stefan