Return-Path: Received: from mail-yk0-f173.google.com ([209.85.160.173]:36734 "EHLO mail-yk0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752945AbbDAUC6 (ORCPT ); Wed, 1 Apr 2015 16:02:58 -0400 Received: by ykcn8 with SMTP id n8so16712179ykc.3 for ; Wed, 01 Apr 2015 13:02:57 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20150401195603.GG3040@fieldses.org> References: <1427751843.1013981.247256753.2BA43388@webmail.messagingengine.com> <1427811676.1314276.247565589.4E14003B@webmail.messagingengine.com> <20150401175437.GD3040@fieldses.org> <1427911337.1794160.248190485.1F161545@webmail.messagingengine.com> <20150401185146.GE3040@fieldses.org> <1427915047.1810469.248215805.54189CB6@webmail.messagingengine.com> <20150401195603.GG3040@fieldses.org> Date: Wed, 1 Apr 2015 16:02:57 -0400 Message-ID: Subject: Re: file xfer over NFSv4 with 'sync' ~300X slower than with 'async' ? From: Trond Myklebust To: "J. Bruce Fields" Cc: lyndat3@your-mail.com, Linux NFS Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, Apr 1, 2015 at 3:56 PM, J. Bruce Fields wrote: > On Wed, Apr 01, 2015 at 12:04:07PM -0700, lyndat3@your-mail.com wrote: >> Hi >> >> > > Yes. This is a common source of confusion. In retrospect maybe the >> > > export sync/async option should have had a different name from the >> > > client mount option.--b. >> > > >> > >> > Do we still need a server 'async' export option? Who is still using >> > NFSv2 for any type of performance-critical work? >> >> >> Just to be clear -- MY pebkac was that I'd set the CLIENT mount as 'sync' -- based on the misunderstanding that write integrity required it 'everywhere' -- on the export AND the mount -- and that 'async' was potentially unsafe. >> >> The server was always exporting 'sync'. > > Yeah, understood, I just meant that if we'd originally named that export > option, I don't know, "trash_me_on_reboot", then you wouldn't have > gotten the "don't use async, it's unsafe" idea, and wouldn't have gotten > into this mess. But, too late to do anything about that, I guess. > I like that name... Just set it up as an alias for 'async' in /etc/exports and add nagware to exportfs. Trond