On Tue, Aug 12, 2014 at 10:07 AM, Eric Blake <ebl...@redhat.com> wrote:
> On 08/12/2014 07:45 AM, 吴兴博 wrote: > > [please don't top-post on technical lists] > > Sorry about that.. > > Thanks for your information. It's really helpful. > > I think adding a bitmap alongside the raw file ( or just within that > file) > > Umm, how do you propose to add a bitmap within a raw file? The moment > the file contains metadata, it is no longer raw, but some other format. > You'd need a way to reliably delineate the portion of the file that > contains the bitmap and therefore must not be exposed to the guest. > > Yes a agree. It's not raw anymore. It should be some 'lightweight' format. > would be suffice to distinguish between present or in backing file. > > The idea in FVD looks similar to 'addcow'---use bitmap but delegating > > allocation to FS. However FVD seems to have been ignored by community. > > Care to give a pointer to a URL describing the FVD format? > > http://lists.nongnu.org/archive/html/qemu-devel/2011-01/msg00398.html This thread could be the clearest message on FVD. It also has a paper published on USENIX conference. https://www.usenix.org/event/atc11/tech/final_files/Tang.pdf > -- > Eric Blake eblake redhat com +1-919-301-3266 > Libvirt virtualization library http://libvirt.org > >
