From: Sev Binello Subject: Re: [NFS] export dir thru 2 diff path names Date: Mon, 10 Nov 2008 13:51:23 -0500 Message-ID: <491882AB.6070908@bnl.gov> References: <478B90A1.5000900@bnl.gov><1200330387.7470.11.camel@heimdal.trondhjem.org><478B9A64.5030903@bnl.gov> <49147E79.6000508@bnl.gov><20081109155831.GA24508@fieldses.org> <49185984.8010500@bnl.gov><20081110164947.GA17050@fieldses.org> <491869F0.1000505@bnl.gov> <620E93B2E5CC3B46BD811165E3335B8702F374A0@0461-its-exmb02.us.saic.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: "J. Bruce Fields" , nfs@lists.sourceforge.net To: "Murata, Dennis" Return-path: Received: from neil.brown.name ([220.233.11.133]:39814 "EHLO neil.brown.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754695AbYKJSwH (ORCPT ); Mon, 10 Nov 2008 13:52:07 -0500 Received: from brown by neil.brown.name with local (Exim 4.69) (envelope-from ) id 1Kzbrp-000881-CM for linux-nfs@vger.kernel.org; Tue, 11 Nov 2008 05:52:05 +1100 In-Reply-To: <620E93B2E5CC3B46BD811165E3335B8702F374A0-9/h0XwadXgnyjpQT3Si/rsM9+qvyE0V4QQ4Iyu8u01E@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: Murata, Dennis wrote: > I just tested this on a SL4.7 (RHEL 4.7 variant) using a RHEL 4.4 nfs > server. I did get the messages from exportfs about duplicate export > entries. On the client I was able to mount both the symlink and the > actual directory. They look like separate mounts. There are two > entries in /proc/mounts and in /etc/mtab, one with the actual directory > path, one with the symlink path. I am using autofs to mount the > directories, not hardcoded. Are you using newer distributions? > I tested on RHEL 4.6. Interesting that you can still mount either one. On the server an exportfs only shows the real path as exported. > What problems will I cause by doing this? I am using the symlink path > as the installation path for an application. The idea is a newer > version can be installed into a different directory, then after testing > the symlink will be changed to the new installation. Other applications > that reference the application will always use the symlink path, as well > as any user scripts. > > Wayne > > >> -----Original Message----- >> From: linux-nfs-owner@vger.kernel.org >> [mailto:linux-nfs-owner@vger.kernel.org] On Behalf Of Sev Binello >> Sent: Monday, November 10, 2008 11:06 AM >> To: J. Bruce Fields; nfs@lists.sourceforge.net >> Subject: Re: [NFS] export dir thru 2 diff path names >> >> J. Bruce Fields wrote: >> >>> On Mon, Nov 10, 2008 at 10:55:48AM -0500, Sev Binello wrote: >>> >>> >>>> Well the simplest approach doesn't work. >>>> i.e put symb link and actual path in the export file & try >>>> >> exporting >> >>>> it Exportfs dereferences the link and states that >>>> >> duplicates are not allowed. >> >>>> >>>> >>> OK, makes sense. >>> >>> You could mount --bind the filesystem at the other location >>> >> instead of >> >>> symlinking. >>> >>> The filehandles given to the client will be the same across the two >>> exports. If you mount both from the same client, behavior may vary >>> across different clients (for example, as to whether they >>> >> attempt to >> >>> share caches between the two), but I think it'd work. >>> >>> (The question "why??!!??" does come to mind, though.) >>> >>> >>> >> Need to make a path change to how file systems are mounted >> and exported on the servers This then required a wholesale >> change to clients so they mount the correct path. >> Not an issue for linux. >> But since we don't administer windows pcs and they also mount >> the same file system, wanted to see if we could let them stay >> the way they were for now. >> >> We're just going to go ahead and have to coordinate this >> with windows guys. >> >> -Sev >> >>> --b. >>> >>> >>> >>>> -Sev >>>> >>>> J. Bruce Fields wrote: >>>> >>>> >>>>> On Fri, Nov 07, 2008 at 12:44:25PM -0500, Sev Binello wrote: >>>>> >>>>> >>>>> >>>>>> Can anyone tell me if it's ok to export the same file system >>>>>> through 2 different paths ( one is a link) ? >>>>>> >>>>>> >>>>>> >>>>> I actually don't know. You could try it and tell us what >>>>> >> you find >> >>>>> out.... >>>>> >>>>> If you're exporting something *containing* the symlink >>>>> >> and expecting >> >>>>> the client to traverse into the filesystem, be aware that >>>>> >> symlinks >> >>>>> over NFS are actually interpreted (and followed) on the >>>>> >> client--so >> >>>>> they're interpreted as *client-side* paths, not server-side. >>>>> >>>>> If the path you're exporting is itself a symlink--it probably >>>>> depends on how nfs-utils treats symlinks found in >>>>> >> /etc/exports. I'd >> >>>>> have to try it or check the code. >>>>> >>>>> Another way to export the filesystem in two different >>>>> >> places would >> >>>>> be with mount --bind. >>>>> >>>>> --b. >>>>> >>>>> >>>>> >>>> -- >>>> >>>> Sev Binello >>>> Brookhaven National Laboratory >>>> Upton, New York >>>> 631-344-5647 >>>> sev-IGkKxAqZmp0@public.gmane.org >>>> >>>> >>>> >> -------------------------------------------------------------- >> ----------- >> This SF.Net email is sponsored by the Moblin Your Move >> Developer's challenge Build the coolest Linux based >> applications with Moblin SDK & win great prizes Grand prize >> is a trip for two to an Open Source event anywhere in the >> world http://moblin-contest.org/redirect.php?banner_id=100&url=/ >> _______________________________________________ >> NFS maillist - NFS@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/nfs >> _______________________________________________ >> Please note that nfs@lists.sourceforge.net is being discontinued. >> Please subscribe to linux-nfs@vger.kernel.org instead. >> http://vger.kernel.org/vger-lists.html#linux-nfs >> >> -- >> To unsubscribe from this list: send the line "unsubscribe >> linux-nfs" in the body of a message to >> majordomo@vger.kernel.org More majordomo info at >> http://vger.kernel.org/majordomo-info.html >> >> -- Sev Binello Brookhaven National Laboratory Upton, New York 631-344-5647 sev-IGkKxAqZmp0@public.gmane.org ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs _______________________________________________ Please note that nfs@lists.sourceforge.net is being discontinued. 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