Re: [Qemu-devel] [PATCH v4 0/6] Efficient VM backup for qemu

[Kevin Wolf]

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