Re: [gentoo-user] How to set udev rule?

[Alex Schuster <wonko@wonkology.org>]

Jesús Guerrero writes:

> On Sun, August 30, 2009 21:38, Dirk Heinrichs wrote:
> > Am Sonntag 30 August 2009 19:29:39 schrieb Alex Schuster:
> >> I have to change the bus from usb to scsi, then it works. But what
> >> about unmounting? Is is possible to have it unmounted after I pull the
> >> memory stick?
> >
> > How do want to umount something that's not there anymore? You have to
> > umount _before_ you pull it.
>
> You can force the umount using -l (no, it's not documented in the man
> page). You can use this to umount a volume *after* it has been physically
> removed.

The -l is not necessary here, a simple umount is enough.

> And some people use this crap on udev rules to remove the
> volume when they unplug the pendrive. 

Yes, this very rule would be nice to have :)

> Then they wonder why the heck
> the file is not where it should be. I guess they never heard of cached
> writes.
>
> The correct thing to do is of course to umount it before,
> and then unplug it or whatever.

I do so, it makes me feel better, but I wonder whether it is _really_ 
necessary. I see Windows users do this all the time, without any problem 
yet. Of course, the wait a little after writing to it, but a few seconds 
after the blinking stops seem to be enough. And people are lazy, I know my 
Linux users _will_ just plug the stick. Using the KDE4 automounter, the 
device will be unmounted automatically in this case, but I am looking for a 
solution without KDE4, and as few user interaction as possible. The udev 
mouting rule is nice, but it leaves a lot of mounts when plugging in and out 
repeatedly.

When the system is mostly idle, I guess the writing to the stick would not 
be delayed for a long time, so this should be quite safe. At least if the 
data is not that important. And if there are no writes, I see no problem at 
all.

There also is the sync option to mount, it should not be used on media with 
limited number of write cycles, but I also guess that for my purposes this 
would not matter.

	Wonko