From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:57723 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755086Ab2AQQkp (ORCPT ); Tue, 17 Jan 2012 11:40:45 -0500 Date: Tue, 17 Jan 2012 11:40:44 -0500 From: "J. Bruce Fields" To: Bertrand Jacquin Cc: linux-nfs@vger.kernel.org Subject: Re: I/O Wait on exportfs Message-ID: <20120117164044.GC13977@fieldses.org> References: <20120117142945.GA19990@lady-voodoo.exosec.local> <20120117150901.GA12274@fieldses.org> <20120117154319.GB19990@lady-voodoo.exosec.local> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: <20120117154319.GB19990@lady-voodoo.exosec.local> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, Jan 17, 2012 at 04:43:19PM +0100, Bertrand Jacquin wrote: > Le mardi 17 janvier 2012 à 16h09, « J. Bruce Fields » a écrit : > > On Tue, Jan 17, 2012 at 03:29:45PM +0100, Bertrand Jacquin wrote: > > > For a specific case I have /etc/exports with 1281 entries as I need > > > mount --bind to be exported to NFS Clients too. > > > > Could you explain what you mean by that? > > In this case, I need /srv/mail to be exported to clients. But for a 1 > month period, I need folders present in /srv/mail2 to be accessible in > /srv/mail. > > We are moving datas to a SAN, and to avoid modifying any mail configuration > (and the long list depending on it), I mount /srv/mail2 subdirectory to > /srv/mailsubdirectory until all subdirectory are migrated : > > # mount /dev/drbd5 /srv/mail > # mount /dev/mapper/iqn.dXX:san1.target0-lun0 /srv/mail2 > # > # mount --bind /srv/mail2/user1 /srv/mail/user1 > > To make /srv/mail2/user1 data visible for NFS client, I need to use > crossmnt options in /etc/exports as nohide is client per client. > > exports(5) say : > > Thus when a child filesystem "B" is mounted on a parent "A", setting > crossmnt on "A" has the same effect as setting "nohide" on B. > > But I can't say that this had work at all, but adding child filesystem > in /etc/export, then 'mount -o remount' NFS partition on client fix > that. I'm maybe wrong, but my tests put me in that way. That's a bug, it should be enough just to export /srv/mail, and the mounts underneath should then automatically be exported. Hm--there have been a couple fixes in that area recently. You might try building the most recent nfs-utils. Then you shouldn't need to list every subexport explicitly in /etc/exports. (That may not solve your performance problem, though.) --b. > > > > Since I have ~1100 entries, reexporting /etc/exports have some bad > > > effects to connected clients, load rise to ~500 for 4/5 minutes, this is > > > always reproducible. > > > > > > This was using 'exportfs -ra'. I did try with 'exportfs > > > 192.168.0.1:/srv/mail/1234' to avoid reexport every directories, and > > > the sync process but the result is the same. > > > > Does a -t option (see rpc.mountd(8)) help? > > This is interesting > > Bertrand > > -- > Bertrand Jacquin, EXOSEC (http://www.exosec.fr/) > ZAC des Metz - 3 Rue du petit robinson - 78350 JOUY EN JOSAS > Tel: +33 1 30 67 60 65 - Fax: +33 1 75 43 40 70 > GSM: +33 6 71 01 70 30 - mailto:bjacquin@exosec.fr