From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 28 Nov 2014 10:57:45 +0100 From: Gilles Chanteperdrix Message-ID: <20141128095745.GB3832@hermes> References: <54775097.30705@siemens.com> <20141127181823.GK7842@hermes> <547772AF.108@siemens.com> <20141127191438.GI24110@csclub.uwaterloo.ca> <20141127203400.GP7842@hermes> <54778CF6.6000909@siemens.com> <20141127231527.GC24076@hermes> <5478430B.9030602@siemens.com> <20141128095038.GA3832@hermes> <547846AC.6070204@siemens.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <547846AC.6070204@siemens.com> Subject: Re: [Xenomai] [pull] forge: Adjust default registry mount point List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Xenomai On Fri, Nov 28, 2014 at 10:55:56AM +0100, Jan Kiszka wrote: > On 2014-11-28 10:50, Gilles Chanteperdrix wrote: > > On Fri, Nov 28, 2014 at 10:40:27AM +0100, Jan Kiszka wrote: > >> On 2014-11-28 00:15, Gilles Chanteperdrix wrote: > >>> On Thu, Nov 27, 2014 at 09:43:34PM +0100, Jan Kiszka wrote: > >>>> On 2014-11-27 21:34, Gilles Chanteperdrix wrote: > >>>>> On Thu, Nov 27, 2014 at 02:14:38PM -0500, Lennart Sorensen wrote: > >>>>>> On Thu, Nov 27, 2014 at 07:51:27PM +0100, Jan Kiszka wrote: > >>>>>>> On 2014-11-27 19:18, Gilles Chanteperdrix wrote: > >>>>>>>> According to the filesystem hierarchy standard, /mnt is the standard > >>>>>>>> place for "temporarily mounted filesystems". > >>>>>>>> > >>>>>>>> http://en.wikipedia.org/wiki/Filesystem_Hierarchy_Standard > >>>>>>> > >>>>>>> Right, another reason to NOT mess around with it: if something was > >>>>>>> temporarily mounted there, we will create the mountpoint inside that > >>>>>>> filesystem with unforeseeable side effects. > >>>>>> > >>>>>> I always read that as "temporarily mounted there by the admin or some > >>>>>> other human". Certainly not automatic mounts by software. There is a > >>>>>> reason /media and such exists on many distributins. > >>>>> > >>>>> I would not venture an "always", autofs for instance, used to mount > >>>>> things under /mnt. and /media has not always existed either, we used > >>>>> /mnt/cdrom. > >>>> > >>>> FHS on /mnt purpose: > >>>> > >>>> "This directory is provided so that the system administrator may > >>>> temporarily mount a filesystem as needed. The content of this directory > >>>> is a local issue and should not affect the manner in which any program > >>>> is run." > >>>> > >>>> I think this makes it crystal clear that Xenomai is not supposed to > >>>> touch it. > >>> > >>> Just to add another argument. I just asked a friend who is a > >>> professional sysadmin. He creates directory under /mnt and mount > >>> things under these directories. So, I am not sure the standard is > >>> even applied by the people who should use it. > >>> > >>> If you read on the last site I sent, under the /media article: > >>> > >>> Amid much controversy and consternation on the part of system and > >>> network administrators a directory containing mount points for > >>> removable media has now been created. Funnily enough, it has been > >>> named /media. > >>> > >>> Are you sure, 100% sure, that every Xenomai user expects to be able > >>> to use /mnt as a mount point? Or that they will create directories > >>> under /mnt like everybody has been doing since Linux exists? > >> > >> I'm both absolutely sure that a) has to be left alone by Xenomai because > >> of requirements of the FHS and the way /mnt is used and b) we should try > >> hard to avoid creating temporary dirs in persistent filesystems. > > > > This is ridiculous. Because the standard changed, and one > > distribution, Debian, decided to follow the new standard, which > > seems to be not widely accepted, and even controversial, you want to > > impose what Debian does to everybody. The distribution I use has > > mount points under /mnt. So, why following Debian and not the > > distribution I use, and what sysadmin have been doing for ages? > > > > You want the mount point to be somewhere else? Fine, put a symbolic > > link. > > > > mkdir /run/xenomai > > ln -s /run/xenomai /mnt/xenomai > > Again, this is not acceptible as /mnt changes all the time and exposes > various remote filesystems which will hide that link. You are missing the point. Yes, Debian does that, but not all distribution. Other distributions do not do that. -- Gilles.