qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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


From: MORITA Kazutaka
Subject: Re: [Qemu-devel] [RFC PATCH 1/1] ceph/rbd block driver for qemu-kvm
Date: Mon, 24 May 2010 23:01:01 +0900
User-agent: Wanderlust/2.14.0 (Africa) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (Gojō) APEL/10.7 Emacs/22.2 (x86_64-pc-linux-gnu) MULE/5.0 (SAKAKI)

At Mon, 24 May 2010 14:56:29 +0300,
Avi Kivity wrote:
> 
> On 05/24/2010 02:42 PM, MORITA Kazutaka wrote:
> >
> >> The server would be local and talk over a unix domain socket, perhaps
> >> anonymous.
> >>
> >> nbd has other issues though, such as requiring a copy and no support for
> >> metadata operations such as snapshot and file size extension.
> >>
> >>      
> > Sorry, my explanation was unclear.  I'm not sure how running servers
> > on localhost can solve the problem.
> >    
> 
> The local server can convert from the local (nbd) protocol to the remote 
> (sheepdog, ceph) protocol.
> 
> > What I wanted to say was that we cannot specify the image of VM. With
> > nbd protocol, command line arguments are as follows:
> >
> >   $ qemu nbd:hostname:port
> >
> > As this syntax shows, with nbd protocol the client cannot pass the VM
> > image name to the server.
> >    
> 
> We would extend it to allow it to connect to a unix domain socket:
> 
>    qemu nbd:unix:/path/to/socket
> 
> The server at the other end would associate the socket with a filename 
> and forward it to the server using the remote protocol.
> 

Thank you for the explanation.  Sheepdog could achieve desired
behavior by creating socket files for all the VM images when the
daemon starts up.

> However, I don't think nbd would be a good protocol.  My preference 
> would be for a plugin API, or for a new local protocol that uses 
> splice() to avoid copies.
> 

Both would be okay for Sheepdog.  I want to take a suitable approach
for qemu.

Thanks,

Kazutaka



reply via email to

[Prev in Thread] Current Thread [Next in Thread]