Return-Path: linux-nfs-owner@vger.kernel.org Received: from natasha.panasas.com ([67.152.220.90]:49844 "EHLO natasha.panasas.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753308Ab1K2W7I (ORCPT ); Tue, 29 Nov 2011 17:59:08 -0500 Message-ID: <4ED563AC.5040501@panasas.com> Date: Tue, 29 Nov 2011 14:58:52 -0800 From: Boaz Harrosh MIME-Version: 1.0 To: Trond Myklebust CC: Peng Tao , , , Garth Gibson , Matt Benjamin , Marc Eshel , Fred Isaman Subject: Re: [PATCH 0/4] nfs41: allow layoutget at pnfs_do_multiple_writes References: <1322887965-2938-1-git-send-email-bergwolf@gmail.com> <4ED54FE4.9050008@panasas.com> <4ED55399.4060707@panasas.com> <1322603848.11286.7.camel@lade.trondhjem.org> <4ED55F78.205@panasas.com> <1322606842.11286.33.camel@lade.trondhjem.org> In-Reply-To: <1322606842.11286.33.camel@lade.trondhjem.org> Content-Type: text/plain; charset="UTF-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: On 11/29/2011 02:47 PM, Trond Myklebust wrote: > On Tue, 2011-11-29 at 14:40 -0800, Boaz Harrosh wrote: >> On 11/29/2011 01:57 PM, Trond Myklebust wrote: >>>> Also Files when they will support segments and servers that request segments, >>>> like the CEPH server, will very much enjoy the above, .i.e: Tell me the amount >>>> you know you want to write. >>> >>> Why would we want to add segment support to the pNFS files client??? >>> Segments are a nuisance that multiply the amount of unnecessary chitchat >>> between the client and the MDS without providing any tangible >>> benefits... >>> >> >> Your kidding right? >> >> One: it is mandated by the Standard, This is not an option. So a perfectly >> Standard complaint server is not Supported by Linux because we don't see >> the point. > > Bollocks.. Nothing is "mandated by the Standard". If the server doesn't > give us a full layout, then we fall back to write through MDS. Why dick > around with crap that SLOWS YOU DOWN. > NO! MAKE YOU FASTER. The kind of typologies I'm talking about a single layout get ever 1GB is marginal to the gain I get in deploying 100 of DSs. I have thousands of DSs I want to spread the load evenly. I'm limited by the size of the layout (Device info in the case of files) So I'm limited by the number of DSs I can have in a layout. For large files these few devices become an hot spot all the while the rest of the cluster is idle. This is not a theory, we meet these problems ever day. >> Two: There are already file-layout servers out there (multiple) which are >> waiting for the Linux files-layout segment support, because the underline >> FS requires Segments and now they do not work with the Linux client. These >> are CEPH and GPFS and more. > > Then they will have a _long_ wait.... > OK, so now I understand. Because when I was talking to Fred before BAT and during It was very very peculiar to me why he is not already done with that simple stuff. Because usually Fred is such a brilliant fast programmer that I admire, and that simple crap? But now that explains > Trond > Heart