Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-wi0-f178.google.com ([209.85.212.178]:50704 "EHLO mail-wi0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756652Ab3KMEHV (ORCPT ); Tue, 12 Nov 2013 23:07:21 -0500 Received: by mail-wi0-f178.google.com with SMTP id hn6so205120wib.11 for ; Tue, 12 Nov 2013 20:07:20 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <29447.1383230746@obiwan.sandelman.ca> References: <20131031141538.GA621@fieldses.org> <29447.1383230746@obiwan.sandelman.ca> Date: Wed, 13 Nov 2013 09:37:20 +0530 Message-ID: Subject: Re: Need help with NFS Server SUNRPC performance issue From: Shyam Kaushik To: Bruce Fields Cc: linux-nfs@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-nfs-owner@vger.kernel.org List-ID: Hi Bruce, Can you pls suggest how we can formalize this hack into a proper fix? Thanks. --Shyam On Thu, Oct 31, 2013 at 8:15 PM, Michael Richardson wrote: > > >> I am chasing a NFS server performance issue on Ubuntu > >> 3.8.13-030813-generic kernel. We setup 32 NFSD threads on our NFS > >> server. > > I have been also trying to figure out NFS performance issues at my home > office. Server is ubuntu precise (3.2.0-55, old, true) kernel, and clients > are mostly a mix of Debian versions (mostly virtualized XEN). > GbE over a VLAN is setup just for storage, and mostly IPv6 connections. > > J. Bruce Fields wrote: > > Would you be willing to test an upstream kernel and/or some patches? > > Sounds like you're using only NFSv4? > > I'm also willing to; my preference would be to build a generic 3.10 or 3.11 > kernel with NFS as a module, and then update the NFS code, but I > haven't gotten around to scheduling some time to reboot a bunch. > > What I observe is huge TCP send queues on the server and what appears to be > head of queue blocking on the client. This looks like a client issue to me, > and for at least one client (my mpd/shoutcast server), I'm happy to reboot > it regularly... I notice the NFS delays because the music stops :-) > > There are some potential instabilities in frequency of IPv6 Router > Advertisements due to a bug in the CeroWRT, which initially I was blaming, > but I'm no longer convinced, since it happens over IPv4 on the storage VLAN > too. > > Shyam, please share with me your testing strategy. > > -- > ] Never tell me the odds! | ipv6 mesh networks [ > ] Michael Richardson, Sandelman Software Works | network architect [ > ] mcr@sandelman.ca http://www.sandelman.ca/ | ruby on rails [ > > > > >