Re: Formatting a Flash Drive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 01/13/2011 02:10 AM, RiverWind wrote:
I can not understand for the life of me how the flash drive
all of a sudden became a "read only" media, let alone how to
remedy the matter.

My first thought is that the drive is mounted under/by a different user. If you run under the user "riverwind", and the drive was mounted under the "root" account instead of your user account, it would display exactly this read-only behavior.

To find out you can do the following:

 bash[1]$  mount

This give you a list of mounted devices and where they're mounted. You're interested in the one that's mounted where your drive is. Usually this is something like /media/usb0 on a Debian system, though I don't know where it ended up.

You can then go into the directory containing that mount-point and take a listing. Assuming as mentioned above that your drive is mounted at /media/usb0 then you want to

  bash[2]$ cd /media
  bash[3]$ ls -lFd usb0

This will do a long/wide ("-l") listing of that directory for the mount-point. The fields of interest are the owner information and the permissions. In a world where the drive was mounted by your user, you should likely find "riverwind riverwind" (your username and primary group which most distros create as your name). However my suspicion is that you'll note "root root" ("root" is the owning username and "root" is the owning group). That alone isn't enough to prevent you from accessing it, but (depending on your settings) might be enough to prevent you from writing/changing to the media (including deleting).

You can then look at the permissions column to see what permissions that folder grants. My guess is that you'll find "drwxr-xr-x" which means that, if it's not owned by your user, that you (part of "other", the last 3 characters) can read files ("r") and list directory contents ("x"), but not write changes (the penultimate character is a "-" instead of a "w").

Including the output of that "ls" command in a reply would help if the following resolution ideas don't work.


THAT SAID. (Sorry, I tend to ramble)

To fix you need to get that drive remounted under your user. A couple options might work for you depending on how interested you are in the dirty details. The fastest/easiest solution might be to shut down the computer, remove the drive, start up the computer, log in, and then re-insert the drive. Hopefully that will cause it to notice that you're logged in and should be the one to "own" the drive.

Personally, I abhor rebooting, so the technical solution to that would be to un-mount the drive as superuser:

  bash[4]$ sudo umount /media/usb0

Once that completes, you can either try re-mounting it yourself as your non-root user:

  bash[5]$ mount /media/usb0

or if you get a "you don't have permission to mount that here" message (per your /etc/fstab which would also be helpful to include in an email if you're willing and still having trouble), you can safely pull out the drive and re-insert it (hoping that it properly detects you as the user this time instead of root).

There's a delicate interplay between your /etc/fstab file which tells where/who/how things get mounted, and your hotplug/dbus/hal which may try to do the auto-mounting for you. How this works varies between distros, so I'm not sure I can help much more.

Hope this gets you further towards your goals.

-tim


_______________________________________________
Blinux-list mailing list
Blinux-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/blinux-list


[Index of Archives]     [Linux Speakup]     [Fedora]     [Linux Kernel]     [Yosemite News]     [Big List of Linux Books]