On Wed, Feb 20, 2013 at 04:04:49PM +0000, Dietmar Maurer wrote: > > The backup writer abstraction is a special case interface somewhere > > between an image format and live migration. I'd prefer it if the backup > > block job stuck to BlockDriverState as the destination for backup data. > > Then you could save a point-in-time copy of a disk to a raw or even > > qcow2 image. > > backup needs to work on non-seekable pipes.
In _your_ use case. That means that we should support using non-seekable pipes, but it doesn't mean that any other use case is irrelevant. In fact I think backing up to a normal raw or qcow2 image file is the interesting case for the majority of people. Kevin