From: "Murata, Dennis" Subject: Re: [NFS] export dir thru 2 diff path names Date: Mon, 10 Nov 2008 11:28:04 -0800 Message-ID: <620E93B2E5CC3B46BD811165E3335B8702F3759D@0461-its-exmb02.us.saic.com> 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> <491882AB.6070908@bnl.gov> <620E93B2E5CC3B46BD811165E3335B8702F37542@0461-its-exmb02.us.saic.com> <4918859C.6080608@bnl.gov> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: "J. Bruce Fields" , nfs@lists.sourceforge.net To: "Sev Binello" Return-path: Received: from neil.brown.name ([220.233.11.133]:36240 "EHLO neil.brown.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750773AbYKJT0S (ORCPT ); Mon, 10 Nov 2008 14:26:18 -0500 Received: from brown by neil.brown.name with local (Exim 4.69) (envelope-from ) id 1KzcOt-0008FH-G6 for linux-nfs@vger.kernel.org; Tue, 11 Nov 2008 06:26:15 +1100 In-Reply-To: <4918859C.6080608-IGkKxAqZmp0@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: That really is the 64K question. During my initial testing, I exported the parent directory. Now I am explicitly exporting the installation directories, where I see the exportfs message. In the messages log file on the server the mount request from the client is always the actual directory. Wayne > -----Original Message----- > From: Sev Binello [mailto:sev-IGkKxAqZmp0@public.gmane.org] > Sent: Monday, November 10, 2008 1:04 PM > To: Murata, Dennis > Cc: J. Bruce Fields; nfs@lists.sourceforge.net > Subject: Re: [NFS] export dir thru 2 diff path names > > Hi - > Yeah, I see. > So it actually looks like you can do this. > I'm not 100% sure if safe --though it looks it -- so I'll > probably not use it for this application. > > Thanks > -Sev > > Murata, Dennis wrote: > > That is correct, exportfs only shows the actual directory. > The client > > seems to be able to mount the directory with either. > > > > Wayne > > > > > >> -----Original Message----- > >> From: Sev Binello [mailto:sev-IGkKxAqZmp0@public.gmane.org] > >> Sent: Monday, November 10, 2008 12:51 PM > >> To: Murata, Dennis > >> Cc: J. Bruce Fields; nfs@lists.sourceforge.net > >> Subject: Re: [NFS] export dir thru 2 diff path names > >> > >> 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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