One of my Kingston USB thumb drives suddenly became write-protected recently. If I try to update one of its .txt files, Linux tells me that the file is write-protected. 'Properties' shows me as its owner with read and write privileges. Actually all the drive's files and directories are write-protected. I've tried chown and chmod to no avail. I am not familar enough with /etc/fstab to put it to work.

By the way, I've seen too many similar reports on-line and yet not one link seems to help my case. Any advice will be much appreciated.

julianvb

If it suddenly became ready only then:
Does it have a write protect switch that got accidentally moved to the wrong position?
Is the file system full?
The drive could be failing, backup the files before continuing to play.

You didn't indicate whether you have tried using the drive with windows or another computer. chmod and chown do not work on FAT32 file systems.

Thanks very much for your excellent points.

(1)My USB drive has no visible external switch and it's not full. The problem may have developed when I used it with Windows XP a couple of times recently. Tonight I checked it out on a Windows XP machine and got a hint that it might be corrupted. A particular .txt file contains some invalid chars embedded near the end which I can see shown in red but they returned after I deleted them with gedit. I've even tried using the following command to turn off the vfat usb drive's write protection and received a positive screen confirmation from Linux.

#sudo hparm -r0 /dev/sdb1

/dev/sdb1:
setting readonly to 0 (off)
readonly=0 (off).

As you pointed out, this command might not really work on FAT32 file systems just as chown and chmod don't.

(2) I've just copied the entire 'bad' usb drive's contents to a 1TB Western Digital USB hard drive for safekeeping.
As to be expected, all the newly copied files and directories are write-protected also.

julianvb

You copied the contents to a new drive and again the files are read only? Could the partition or drive be mounted read only somehow? Or user permissions?

Are you mounting this manually (in a terminal) or is something auto-mounting it? If so, did you check to see if it was somehow mounted read-only?

A would agree that your flash drive could potentially be on the brink of failure, you should probably copy everything to somewhere else.

Hope this helps!

Could you post the contents of your fstab?

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Steve Stites

2014-07-02

Hi, Everyone,

Thank you all for your help.

I finally confirmed with the help of Windows XP that the USB drive in question is indeed corrupted. That left me no choice but to re-format it (in Linux naturally).

I recommend Disk Utility highly to everyone. It enables the Linux user to do so many things with a storage device without typing so many terminal commands! I've now reformatted the USB drive with Disk Utility and copied my old files back to it. The drive appears to be working happily without write-protection imposed. Thanks again Disk Utility.

Julianvb

By the way, one can invoke Disk Utility in Ubuntu by typing the following command:

palimpsest

julianvb