Re: [PATCH 0/4] nfs41: allow layoutget at pnfs_do_multiple_writes

[Trond Myklebust <Trond.Myklebust@netapp.com>]

On Tue, 2011-11-29 at 16:20 -0800, Marc Eshel wrote: 
> You ignored my main point, I was talking about the server side, my point 
> was that there is nothing to build on on the serve side since the pNFS 
> Linux server is not happening.
> Marc.

Sorry. I misunderstood your concern. As far as I know, the main problem
there is also one of investment: nobody has stepped up to help Bruce
write a pNFS server.

I'm less worried about this now than I was earlier, because other open
source efforts are gaining traction (see Ganesha - which is being
sponsored by IBM, and projects such as Tigran's java based pNFS server).
The other point is that we've developed client test-rigs that don't
depend on the availability of a Linux server (newpynfs and the pynfs
based proxy).

Cheers
  Trond 

> From:
> Trond Myklebust <Trond.Myklebust@netapp.com>
> To:
> Marc Eshel <eshel@almaden.ibm.com>
> Cc:
> Peng Tao <bergwolf@gmail.com>, bhalevy@tonian.com, Boaz Harrosh 
> <bharrosh@panasas.com>, Garth Gibson <garth@panasas.com>, Fred Isaman 
> <iisaman@netapp.com>, linux-nfs@vger.kernel.org, Matt Benjamin 
> <matt@linuxbox.com>
> Date:
> 11/29/2011 04:08 PM
> Subject:
> Re: [PATCH 0/4] nfs41: allow layoutget at pnfs_do_multiple_writes
> 
> 
> 
> On Tue, 2011-11-29 at 15:49 -0800, Marc Eshel wrote: 
> > The only 1 cent that I can add to this argument is that I was led to 
> > believe by you and others that Linux kernel don't add functionality on 
> the 
> > client side that is not supported on the server side. Last time I made 
> > this point I was told that it is ok if they are of by a version or two. 
> > You made it clear that this is no longer true and that the Linux client 
> > and server are now independent of each other. I spent time working on 
> the 
> > server side believing that the client and server will progress more or 
> > less together, disappointed to find out that it is not the case any 
> more.
> > Marc. 
> 
> I don't know how to manage layout segments in a way that meets the pNFS
> goals of scalability and performance, and neither you nor the pNFS spec
> have told me how to do this.
> 
> If IBM wants a client that implements layout segments, then it is _your_
> responsibility to: 
>      A. Convince me that it is an implementable part of the spec. 
>      B. Provide me with an implementation that deals all with the
>         concerns that I have.
> 
> IOW: nobody has ever promised IBM that the community would do all your
> client work for you. EMC, NetApp and Panasas have implemented (most of)
> the bits that they cared about; any bits that they haven't implemented
> and that you care about are up to you.
> 

-- 
Trond Myklebust
Linux NFS client maintainer

NetApp
Trond.Myklebust@netapp.com
www.netapp.com