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

[MORITA Kazutaka]

At Fri, 21 May 2010 00:16:46 +0200,
Christian Brunner wrote:
> 
> 2010/5/20 Anthony Liguori <address@hidden>:
> >> With new approaches like Sheepdog or Ceph, things are getting a lot
> >> cheaper and you can scale your system without disrupting your service.
> >> The concepts are quite similar to what Amazon is doing in their EC2
> >> environment, but they certainly won't publish it as OpenSource anytime
> >> soon.
> >>
> >> Both projects have advantages and disadvantages. Ceph is a bit more
> >> universal as it implements a whole filesystem. Sheepdog is more
> >> feature complete in regards of managing images (e.g. snapshots). Both

I think a major difference is that Sheepdog servers act fully
autonomously.  Any Sheepdog server has no fixed role such as a monitor
server, and Sheepdog doesn't require any configuration about a list of
nodes in the cluster.


> >> projects require some additional work to become stable, but they are
> >> on a good way.
> >>
> >> I would really like to see both drivers in the qemu tree, as they are
> >> the key to a design shift in how storage in the datacenter is being
> >> built.
> >>
> >
> > I'd be more interested in enabling people to build these types of storage
> > systems without touching qemu.
> 
> You could do this by using Yehuda's rbd kernel driver, but I think
> that it would be better to avoid this additional layer.
> 

I agree.  In addition, if a storage client is a qemu driver, the
storage system can support some features specific to qemu such as live
snapshot from qemu monitor.

Regards,

Kazutaka