Write privilage with USB drive

grenier · 03-06-2005, 08:37 AM

Under 10.1 - both community and official - most usb drive ( FAT formated ) automount and work flawlessly.

There is however a problem as root is the only one to have writing privileges to them. I know the usb drives ultimately don't refer to fstab (which is modified on the fly when you plug and unplug one in). I mostly don't want to change mandrake's behavior with these drives (that means no hard modifying of the fstab).

So, could anyone direct me as to what file I need to alter in order to give standard users writing privilege - I'm guessing it has something to do with udev conf' files, but I haven't been able to pinpoint anything when I went through its documentation.

Thanks for any help you could provide.

opjose · 03-06-2005, 01:31 PM

Eh, this is not QUITE true.

Kudzu automatically adds an entry to /etc/fstab for any newly found USB drive.

It does NOT automatically remove them though, which can lead to a lot of trouble in ID'ing frequently exchanged devices.

Your best bet is to NOT let the system automatically add entries for the drive, and then set the drive to be user mountable via the MCC's own "Partitions" panel.

mac57 · 03-07-2005, 05:25 PM

Another possible workaround. I have this problem with most removable drives that support a linux file system. Only root can write to them. Typically, when I first set it up, I su to root, create a top level directory on the removable drive with the same name as my userid, and then chown that directory to myself. After that, I do all the reading and writing to my userid's directory on the drive. Seems to work well.

To do this, mount the drive (example /mnt/usbdrive)
su to root
cd /mnt/usbdrive
mkdir my_userid
chown my_userid: my_userid

That does the trick - henceforth you will have full write priveledges to /mnt/usbdrive/my_userid

Brian1 · 03-07-2005, 05:45 PM

In your /etc/fstab file add umask=000 to the mount point for device. Example only works for fat or vfat formmated drives.

Code:

/dev/sda1               /mnt/sda1               auto    umask=000,users,noauto,owner,rw,sync,dirsync   0 0 
/dev/sdb1               /mnt/sdb1               auto    umask=000,users,noauto,owner,rw,sync,dirsync   0 0 
/dev/sdc1               /mnt/sdc1               auto    umask=000,users,noauto,owner,rw,sync,dirsync   0 0

I don't use kudzu and turn it off. I do most mounting manually. I just have about 4 of these in my fstab file. I just start mounting from sda1 to sdd1 as needed. Currently in fedora3 Udev and Hal create mount points in etc/fstab as devices are plugged in. I ginore them since when removed they disappear.

As Long as there are only one partition on each device this works very well for me.

Brian1
" Google the Linux way @ http://www.google.com/linux "

mac57 · 03-07-2005, 06:27 PM

Interesting. How do you turn kudzu off - I would love to do this! Bet it speeds up boot times?

Brian1 · 03-07-2005, 06:31 PM

in a terminal and having root access type ' chkconfig --level 345 kudzu off '
It will increase boot some.

Brian1
" Google the Linux way @ http://www.google.com/linux "

mac57 · 03-07-2005, 08:48 PM

Sorry for the dumb question, but is there an equally easy way to turn it back on? Can you point me at any reference material on this (web pages, whatever)? I would like to learn more about chkconfig. Thanks!

Brian1 · 03-09-2005, 04:48 PM

Soory for the delay. Sick yesterday. To turn it back on do the following.
' chkconfig --level 345 kudzu on '

What this does is create the scripts to start in runlevels 3,4,& 5. Not sure which numbered order it does. I seldom do things this way. Mostly use the command to turn off scripts. These scripts are located in /etc/rc.d/init.d. What it does it place them in /etc/rc.d/rc.0 - rc.6. They get a s** for start in that run level ans k** for a stop in that runlevel. Just look over these areas and it should come clear.

Brian1
" Google the Linux way @ http://www.google.com/linux "

grenier · 03-12-2005, 08:43 AM

Well, I should have answered sooner, and thanks for the response.

However, there is no kudzu in Mandrake 10.1 (I checked it up going through the init.d script, the logs, and even the starting up sequence in case I forgot something).

So if somebody knows how mandrake does this hotplugging of USB drives, and where it's set up...