Date: Fri, 21 Mar 2008 09:40:39 +1000 From: Da Rock <rock_on_the_web@comcen.com.au> To: freebsd-questions@freebsd.org Subject: Re: removable devices auto umounting Message-ID: <1206056439.27757.152.camel@laptop2.herveybayaustralia.com.au> In-Reply-To: <20080320131443.GD64490@slackbox.xs4all.nl> References: <1205978132.27757.28.camel@laptop2.herveybayaustralia.com.au> <20080320074312.GB59070@slackbox.xs4all.nl> <1206014137.27757.132.camel@laptop2.herveybayaustralia.com.au> <20080320131443.GD64490@slackbox.xs4all.nl>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, 2008-03-20 at 14:14 +0100, Roland Smith wrote: > On Thu, Mar 20, 2008 at 09:55:37PM +1000, Da Rock wrote: > > > > > I'm just looking into the removable device issue for freebsd. I can see > > > > its easy enough to auto mount a removable device (although I could use > > > > some help getting sd/xd devices working with my card reader), but the > > > > removal seems to come unstuck. > > > > > > > > I have some barely literates on my systems, so I do need to work this > > > > out. Is it possible to use a forced umount to do this? What are the > > > > options here? > > In all honesty, I'm not sure FreeBSD (or any other OS, for that matter) > is suitable for 'barely literates'. A computer is not a toaster. True enough. But at least they know how to plug in and unplug a device- I just don't know if they'll remember to umount first! > > <snip> > > > One (not bullet-proof) workaround might be to use the automounter > > > [amd(8)], and have it unmount very quickly after they stop being > > > active. This requires setting both the 'cache_duration' and > > > 'dismount_interval' options in amd.conf(5) to very low values. > > > > So by active you mean device access? > > I mean access to the auto-mounted directory, or files therein. That'd be perfect then. > > > Or device physical connection? If > > its simply access, than that would be perfect- user enters the mount > > point, > > User needs to plug in the device first! > > And it is actually worse. Depending on if and how the usb device was set > up, you need to use the device daX[sY], where X depends on how many other > da devices are already in use, and the optional Y depends on how it was > sliced (partitioned in DOS parlance). > > Furthermore, you need to know which kind of filesystem is used. Most > thumbdrives are msdosfs, but larger ones might be ntfs as well. > > For msdosfs, I use: > 'mount_msdosfs -m 644 -M 755 -o noatime -o sync -o noexec -o nosuid $DEV $DIR' > I'm sure I could script something to get around that. That shouldn't be too hard, but I take your point: I need to consider nearly all possibilities. > > Also, what docs/how-to's would you suggest for AMD? I looked at the man > > and some freebsd doc pages, but another viewpoint would help. > > Specifically some more docs on the settings you mention. > > I've never used amd, so I can't help you there. :-) > > > Bullet-proof is not exactly necessary- nice, but not critical. > > Suggestions for bullet-proof are very welcome though. What is the worst > > that can happen if dismounting is not entirely successful? Keeping in > > mind that this is mostly a desktop system. > > Last time I tried unplugging a USB device before unmounting it I got a > kernel panic. > > Roland That last point would only occur if the device was still being written to- right? I'm sure my users can be trained at least that far... I will watch out for that though. Thanks for the input. I reckon I can get it working (relatively) smoothly now. Don't suppose you know anything about setting up internal card readers in laptops at all? Trouble is I don't think it's hooked up to the usb bus. Its a Texas Instruments model.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?1206056439.27757.152.camel>