From owner-freebsd-questions@FreeBSD.ORG Mon Apr 26 19:16:51 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 07F8716A4CE for ; Mon, 26 Apr 2004 19:16:51 -0700 (PDT) Received: from mail.seekingfire.com (coyote.seekingfire.com [24.72.10.212]) by mx1.FreeBSD.org (Postfix) with ESMTP id A058143D2D for ; Mon, 26 Apr 2004 19:16:50 -0700 (PDT) (envelope-from tillman@seekingfire.com) Received: by mail.seekingfire.com (Postfix, from userid 500) id 1A08A585; Mon, 26 Apr 2004 20:16:50 -0600 (CST) Date: Mon, 26 Apr 2004 20:16:50 -0600 From: Tillman Hodgson To: FreeBSD-Questions Message-ID: <20040427021650.GQ92049@seekingfire.com> References: <20040426182547.GF92049@seekingfire.com> <20040426183717.GF2771@dan.emsphone.com> <20040426184324.GH92049@seekingfire.com> <20040426184710.GA22344@dan.emsphone.com> <20040426224633.GN92049@seekingfire.com> <20040426230855.GB22344@dan.emsphone.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040426230855.GB22344@dan.emsphone.com> X-Habeas-SWE-1: winter into spring X-Habeas-SWE-2: brightly anticipated X-Habeas-SWE-3: like Habeas SWE (tm) X-Habeas-SWE-4: Copyright 2002 Habeas (tm) X-Habeas-SWE-5: Sender Warranted Email (SWE) (tm). The sender of this X-Habeas-SWE-6: email in exchange for a license for this Habeas X-Habeas-SWE-7: warrant mark warrants that this is a Habeas Compliant X-Habeas-SWE-8: Message (HCM) and not spam. Please report use of this X-Habeas-SWE-9: mark in spam to . X-GPG-Key-ID: 828AFC7B X-GPG-Fingerprint: 5584 14BA C9EB 1524 0E68 F543 0F0A 7FBC 828A FC7B X-GPG-Key: http://www.seekingfire.com/gpg_key.asc X-Urban-Legend: There is lots of hidden information in headers User-Agent: Mutt/1.5.6i Subject: Re: NFS occassionally gives "permission" denied in the middle of a large transfer X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Apr 2004 02:16:51 -0000 On Mon, Apr 26, 2004 at 06:08:56PM -0500, Dan Nelson wrote: > In the last episode (Apr 26), Tillman Hodgson said: > > On Mon, Apr 26, 2004 at 01:47:10PM -0500, Dan Nelson wrote: > > > In the last episode (Apr 26), Tillman Hodgson said: > > > > On Mon, Apr 26, 2004 at 01:37:17PM -0500, Dan Nelson wrote: > > > > > The only time I've seen incorrect permission denied messages is > > > > > when mountd is refreshing the exports list. It's not atomic, > > > > > so there's a small window where the old exports have been > > > > > deleted but the new ones aren't in place yet. > > > > > > > > Is there anything in the default weekly cron jobs that would do > > > > something like that on the file server? > > > > > > I don't think so. Mounting or dismounting local (not NFS) > > > filesystems might do it, but I'm not sure. > > > > Including local filesystems that aren't exported? > > > > If so, that's interesting because I do that in my weekly periodic > > cron job. It's a simple script that umounts a backup partition, > > newfs's it, dumps a local copy of /home over to it, and then > > re-mounts it (for easy user-accessible near-line backup storage that > > doesn't require going to tape for the "real" backup). > > That's probably it, then. /sbin/mount has code that sends SIGHUP to > mountd on any mount operation. Which implies that any manual mount > request, including NFS mounts would, cause the problem. Amd calls the > mount syscall directly, bypassing /sbin/mount. > > Ideally, mountd would be able to compare the current and new export > settings and only update the ones that changed, or have a way to create > a new mountlist and ask the kernel to replace the old one in a single > atomic operation. I'll disable the umount/mount stuff from my dump script for /home and run periodic/weekly by hand to test this. Thanks for the insight! -T -- Unix does not stop you from doing stupid things, because that would also stop you from doing clever things.