* Stefan Hajnoczi <stefa...@gmail.com> [2011-08-22 08:35]: > At KVM Forum Kevin, Christoph, and I had an opportunity to get > together for a Block Layer BoF. We went through the recent "roadmap" > mailing list thread and touched on each proposed feature. > > Here is the block layer roadmap wiki page: > http://wiki.qemu.org/BlockRoadmap > > Kevin: I have moved the runtime WCE toggling to QEMU 1.0 since you > mentioned you want it for the next release. > > My main take-away from the BoF was that integrating support for host > block devices and storage appliances will allow us to reduce the > amount of effort spent on image formats. In order to make image > formats support the desired features and performance we end up > implementing much of the storage stack and file systems in userspace - > code that is duplicated and cannot take advantage of the existing > storage stack.
+1 > > Storage management features are not just available in remote SAN and > NAS appliances anymore. For local storage, btrfs has file-level > clones and thin-dev is significantly improving LVM snapshots. > > Thin-dev is bringing a much more efficient and scalable snapshot model > to LVM. This device-mapper feature will make LVM attractive for high > performance I/O without giving up snapshot and clone features. It > also supports cloning off block devices that are not in the pool (e.g. > external storage, much like QEMU's backing files feature): > https://github.com/jthornber/linux-2.6/tree/thin-dev > > This will not replace image formats overnight because image formats > are still widely used and will continue to be a useful for > transferring and sharing disk images. But focussing on the larger Any thoughts on how to make this easily usable for LVM? If there were an export/import to/from file to LVM? is that sufficient? Anything like this in existence? > storage stack where either local LVM, btrfs, or storage appliances do > the storage management means we exploit those options instead of > implementing equivalent functionality ourselves. QEMU then runs with > plain old raw in more cases. > > Stefan -- Ryan Harper Software Engineer; Linux Technology Center IBM Corp., Austin, Tx ry...@us.ibm.com
