From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761675AbXIUSOk (ORCPT ); Fri, 21 Sep 2007 14:14:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751991AbXIUSOd (ORCPT ); Fri, 21 Sep 2007 14:14:33 -0400 Received: from mx2.netapp.com ([216.240.18.37]:53493 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751002AbXIUSOc (ORCPT ); Fri, 21 Sep 2007 14:14:32 -0400 X-IronPort-AV: E=Sophos;i="4.20,284,1186383600"; d="scan'208";a="106473313" Subject: Re: [NFS] NFS on loopback locks up entire system(2.6.23-rc6)? From: Trond Myklebust To: Chakri n Cc: nfs@lists.sourceforge.net, linux-kernel@vger.kernel.org In-Reply-To: <92cbf19b0709211106n12b1b4ecxc0d415aa097d21b2@mail.gmail.com> References: <92cbf19b0709201722k6265e647x31b7d25bc54b63a0@mail.gmail.com> <1190335423.6763.180.camel@heimdal.trondhjem.org> <92cbf19b0709202012s375c6f54m588987b4bbf552bc@mail.gmail.com> <1190384005.6680.20.camel@heimdal.trondhjem.org> <92cbf19b0709210920p3647788dl11d8c4e0cee1f70f@mail.gmail.com> <1190391881.6680.73.camel@heimdal.trondhjem.org> <92cbf19b0709211106n12b1b4ecxc0d415aa097d21b2@mail.gmail.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Organization: Network Appliance Inc Date: Fri, 21 Sep 2007 14:14:13 -0400 Message-Id: <1190398453.6690.12.camel@heimdal.trondhjem.org> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 X-OriginalArrivalTime: 21 Sep 2007 18:14:15.0286 (UTC) FILETIME=[37EDD960:01C7FC7B] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org No. The requirement for 'hard' mounts is not that the server be up all the time. The server can go up and down as it pleases: the client can happily recover from that. The requirement is rather that nobody remove it permanently before the application is done with it, and the partition is unmounted. That is hardly unreasonable (it is the only way I know of to ensure data integrity), and it is much less strict than the requirements for local disks. Trond On Fri, 2007-09-21 at 11:06 -0700, Chakri n wrote: > Isn't this a strict requirement from client side, asking to guarantee > that a server stays up all the time? > > I have seen many cases, where people go and directly change IP of > their NFS filers or servers worrying least about the clients using > them. > > Can we get around with some sort of congestion logic? > > Thanks > --Chakri > > On 9/21/07, Trond Myklebust wrote: > > On Fri, 2007-09-21 at 09:20 -0700, Chakri n wrote: > > > Thanks. > > > > > > I was using flock (BSD locking) and I think the problem should be > > > solved if I move my application to use POSIX locks. > > > > Yup. > > > > > And any option to avoid processes waiting indefinitely to free pages > > > from NFS requests waiting on unresponsive NFS server? > > > > The only solution I know of is to use soft mounts, but that brings > > another set of problems: > > 1. most applications don't know how to recover safely from an EIO > > error. > > 2. You lose data. > > > > Cheers > > Trond > >