Return-Path: Received: from fieldses.org ([173.255.197.46]:51485 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751964AbbDAT4D (ORCPT ); Wed, 1 Apr 2015 15:56:03 -0400 Date: Wed, 1 Apr 2015 15:56:03 -0400 From: "J. Bruce Fields" To: lyndat3@your-mail.com Cc: Trond Myklebust , Linux NFS Mailing List Subject: Re: file xfer over NFSv4 with 'sync' ~300X slower than with 'async' ? Message-ID: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1427915047.1810469.248215805.54189CB6@webmail.messagingengine.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: 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. --b.