At Sun, 23 May 2010 15:01:59 +0300, Avi Kivity wrote: > > On 05/21/2010 12:29 AM, Anthony Liguori wrote: > > > > I'd be more interested in enabling people to build these types of > > storage systems without touching qemu. > > > > Both sheepdog and ceph ultimately transmit I/O over a socket to a > > central daemon, right? > > That incurs an extra copy. > > > So could we not standardize a protocol for this that both sheepdog and > > ceph could implement? > > The protocol already exists, nbd. It doesn't support snapshotting etc. > but we could extend it. > I have no objection to use another protocol for Sheepdog support, but I think nbd protocol is unsuitable for the large storage pool with many VM images. It is because nbd protocol doesn't support specifing a file name to open. If we use nbd with such a storage system, the server needs to listen ports as many as the number of VM images. As far as I see the protocol, It looks difficult to extend it without breaking backward compatibility. Regards, Kazutaka > But IMO what's needed is a plugin API for the block layer. > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
