Re: [Qemu-devel] [RFC PATCH 1/1] ceph/rbd block driver for qemu-kvm

[Anthony Liguori]

On 05/25/2010 08:36 AM, Avi Kivity wrote:
> We'd need a kernel-level generic snapshot API for this eventually.
>
> > or (2) implement BUSE to complement FUSE and CUSE to enable proper 
> > userspace block devices.
>
> Likely slow due do lots of copying.  Also needs a snapshot API.

The kernel could use splice.

> (ABUSE was proposed a while ago by Zach).
>
> > If you want to use a block device within qemu, you almost certainly 
> > want to be able to manipulate it on the host using standard tools 
> > (like mount and parted) so it stands to reason that addressing this 
> > in the kernel makes more sense.
>
> qemu-nbd also allows this.
>
> This reasoning also applies to qcow2, btw.

I know.

Regards,

Anthony Liguori