Odd behavior of labels on different filesystem types
Kevin Oberman
oberman at es.net
Mon Jul 5 23:53:02 UTC 2010
> Sender: "J. Hellenthal" <jhellenthal at gmail.com>
> Date: Sun, 04 Jul 2010 13:58:30 -0400
> From: jhell <jhell at dataix.net>
>
> On 07/04/2010 12:15, Kevin Oberman wrote:
> >> Sender: "J. Hellenthal" <jhellenthal at gmail.com>
> >> Date: Sun, 04 Jul 2010 01:55:20 -0400
> >> From: jhell <jhell at dataix.net>
> >>
> >> On 07/03/2010 16:51, Kevin Oberman wrote:
> >>> I have run into an odd behavior in 8-stable that I can't see a reason
> >>> for.
> >>>
> >>> If I have a FAT32 formatted removable drive, I get /dev entries for it
> >>> as both /dev/msdosfs/LABEL and /dev/ufsid/ID. When I mount the
> >>> filesystem, the /dev/ufsid label is removed, but the other two remain.
> >>>
> >>> If I have a UFS filesystem on the disk, I have similar devices except
> >>> that the LABEL is /dev/ufs/LABEL. But, when the UFS device is mounted,
> >>> the /dev/ufsid/ID AND the /dev/ufs/LABEL devs are both deleted.
> >>>
> >>> I'm not sure which is "right", but I can't see the reason for the
> >>> different behavior and it has caused a fair bit of trouble when working
> >>> with gnome-mount as I can't unmount a ufs device. When the
> >>> /dev/ufs/LABEL device is created again on the umount, gnome-mount sees a
> >>> new device and immediately re-mounts it.
> >>>
> >>> Can this inconsistency be corrected?
> >>
> >> Can you try to zero out that disk first i.e.
> >> dd if=/dev/zero of=/dev/DISK bs=4m
> >>
> >> Then format your msdos fat part and relabel it. You should not see a
> >> dev/ufsid/ label for this anymore. I believe that for some reason the
> >> ufsid metadata or whatever you want to call it some how has been left
> >> behind and is still being read for whatever reason and can be confirmed
> >> by this.
> >>
> >> As for /dev/ufs/LABEL /dev/ufsid/ID /dev/device when you mount one the
> >> others should disapear so this is correct behavior.
> >
> > Thanks for the suggestion. I will try a device which has never had a UFS
> > file system and see if the ufsid device is created. Looks like the
> > former is an issue with geom tasting and it would be nice to get it
> > fixed, but it is not what is causing my problem. It is the latter issue
> > that causes the problems with gnome-mount.
> >
> > The real issue for me is that /dev/ufs/LABEL is removed on a mount while
> > /dev/msdosfs/LABEL remains. hald easily works around ufsid by ignoring
> > it, but the /dev/FS/LABEL has to be acted upon differently depending on
> > which filesystem is involved.
>
> Do you use those labels for anything ? if not, I worked around this
> while I used gnome for a period with devfs.rules(5) example follows.
>
> rc.conf(5) add devfs_system_ruleset="your_system"
>
> [your_system=10]
> add path 'ufsid' hide
> add path 'msdosfs' hide
> add path 'ufs' hide
> add path 'iso9660' hide
> add path 'reiserfs' hide
> add path 'ntfs' hide
> add path 'ext2fs' hide
> add path 'gpt' hide
>
> And you can do the same for the actual devices that you use a label for,
> so mounting devices like daN can just be done from /dev/label/LABEL.
>
> add path 'da0' hide # Do this only after it is labeled.
> add path 'label/DA0LABEL' mode 0600 user jhell group jhell
>
> With a little toying of the above you should get the desired effect you
> want in gnome. I do find it frustrating having to resort to using only
> generic labels for situations like this and believe firmly that the
> generic label should take precedence over all labels except gpt & ufsid
> and result in the other name-brand labels disappearing not causing this
> frustration to happen. Having the multiple layers of labels available
> IMO is cause for confusion.
>
> Final note before I stretch this out like the Armstrong figurine ;),
> there was a case where I was using the module instead of having
> GEOM_LABEL option built into the kernel, this being loaded after the
> machine was already booted caused some strange results with the labels
> that I know of on 7.2-STABLE. I don't know if this still exists but the
> result from that was multiple labels still being available under /dev
> while its counterpart label was mounted. That caused Gnome/hald to get
> pretty confused.
Thanks. It worked...and it didn't help. Something else in Gnome2.30 is
triggering this, I guess. The disk now mounts as /dev/da0s1d, just like
it should, but it is still re-mounting as soon as I unmount it. This is
a problem for ufs disks, but not for FAT. Since most people are
probably using this for mounting thumb drives which are almost always
FAT, I guess it has not been seen too much.
Guess it's time to take this to the gnome list.
Thanks again.
--
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net Phone: +1 510 486-8634
Key fingerprint:059B 2DDF 031C 9BA3 14A4 EADA 927D EBB3 987B 3751
More information about the freebsd-stable
mailing list