Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-wg0-f46.google.com ([74.125.82.46]:57462 "EHLO mail-wg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752477Ab3JCOTg (ORCPT ); Thu, 3 Oct 2013 10:19:36 -0400 Received: by mail-wg0-f46.google.com with SMTP id k14so2517087wgh.1 for ; Thu, 03 Oct 2013 07:19:35 -0700 (PDT) Message-ID: <524D7CF3.6020306@primarydata.com> Date: Thu, 03 Oct 2013 17:19:31 +0300 From: Benny Halevy MIME-Version: 1.0 To: Ric Wheeler , Christoph Hellwig CC: "J. Bruce Fields" , linux-nfs@vger.kernel.org, Steven Whitehouse , Bob Peterson , Abhijith Das , Andrew Price , Paul Evans Subject: Re: [PATCH RFC v0 05/49] pnfsd: introduce pnfsd header files References: <52481B11.2080407@primarydata.com> <20130929122130.GI21083@infradead.org> <20130929123553.GA7510@infradead.org> <20131001203047.GH16245@pad.fieldses.org> <524C0556.9070705@primarydata.com> <20131002160759.GB27988@infradead.org> <524D0873.40602@primarydata.com> <20131003095511.GA30147@infradead.org> <524D6312.7020709@primarydata.com> <524D6D38.1040506@redhat.com> <20131003131750.GA23408@infradead.org> <524D6EB9.3040309@redhat.com> In-Reply-To: <524D6EB9.3040309@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: On 2013-10-03 16:18, Ric Wheeler wrote: > On 10/03/2013 09:17 AM, Christoph Hellwig wrote: >> On Thu, Oct 03, 2013 at 09:12:24AM -0400, Ric Wheeler wrote: >>>>>> Which in-tree or soon in-tree filesystem do you care about? And why >>>>>> don't we see pnfs support for it submitted instead of the fairly useless >>>>>> gfs2 support? >>>> I picked gfs2 as the initial use case for simplicity and ease of review. >>>> If there is a rough consensus that it's useless and not worthy of inclusion >>>> then the one we care about the most is exofs that has a more complete pnfs >>>> implementation. >>>> >>>> Benny >>>> >>> I don't see having GFS2 supported as a base for pNFS as useless. >>> Christoph, is this a concern about GFS2 being too complicated for >>> normal deployment or a lack in the pNFS support on top of it? >> Fairly useless was specific to the particular implementation: >> >> - which in the stipped down version here only supports DS access for >> reads >> - which in the previous version showed worse performance than always >> going through the MDS >> >> I don't have a problem with using GFS2 by itself, but any implementation >> proposed should actually show signifiant real life benefits before it >> gets merged. >> The question is what is the minimum value for submitting upstream... The thing pnfs over dlm/gfs2 is missing mostly is supporting read/write layout. One could use them load balancing, e.g. by either redirecting to a node holding an exclusive lock on the file, if there is one, or dlm_ino_hash in its absence. Benny > > Makes sense, thanks! > > Ric > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >