usb flash drive gets mounted read only

[oakhilltop]

I have a 16G Kingston Data Traveler that has worked for awhile, but now gets mounted as read only in Mint. I've tried it on 2 computers running Mint 7 and they both mount it read only. I think, sometimes it doesn't get mounted read only, but when I try to transfer a lot of files it switches to read only after a few files were written. When the drive was mounted read only, I unmounted it, put it in a windows pc and it worked fine. Go back to Mint, and its read only. The drive is not that old, so I'm pretty sure I am not beyond its writing limits, and I can delete files in windows.

This happened once before and I re-formatted the drive using gparted. It worked for awhile, but is not back to this problem.

[MaddogF16]

What does your /etc.fstab file look like.

[oakhilltop]

Here it is. Thanks. It did mount as writable for awhile. Last night I copied some large digital video files to it. Today, it seemed like it was writable until I copied a bunch of pictures to it. I had deleted the video files, and there is about 11G free space on it.

/etc/fstab: static file system information.
#
# Use 'vol_id --uuid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc defaults 0 0
# / was on /dev/sda5 during installation
UUID=d068f478-ec1c-425b-8fa5-1ef075ab4d44 / ext3 relatime,errors=remount-ro 0 1
# swap was on /dev/sda6 during installation
UUID=d3a6f6a2-efd1-4686-bda3-31d2633d698a none swap sw 0 0
/dev/scd0 /media/cdrom0 udf,iso9660 user,noauto,exec,utf8 0 0

[oakhilltop]

Hmmm, I shutdown the laptop and turned it back on a few hours later, put the flash drive in and now it is writable again. Perhaps, something goes wrong while copying a bunch of files, then the OS marks it as read only?? Maybe some USB error handling code can't handle the error case.

[mick55]

hi oakhilltop

One of my friends had the exact same problem,
and then he noticed the USB drive had a tiny slide switch
to make it write protected.

Every time he pushed it in or pulled it out
he toggled the switch.

It's probably not your issue, but you never know

peace
mick

[oakhilltop]

No, no switch, but thanks. I tried it this morning and it is writable again. Seems like it goes read only, when I really want to get something done!

I'm not sure how to debug it when it happens.

[MaddogF16]

When it happens take a look at your /etc/fstab file and copy it here.

[Midnighter]

What is it formatted as? Fat32 or NTFS?

[Rank0]

You could also try the command dmesg when the switch to read only happens and see if that log contains anything interesting.

[phd7]

I had the same problem before with one of these with windows (at work, I hasten to add). I tried going into permissions and changing that but nothing worked. Ended up just binning it and sticking with Fusion drives. I have never had a similar problem with them. Hopefully someone else can help you but I would copy the lot to another drive and bin that one.

[cluendo]

I have the same problem with USB stick. in dmesg I've got those lines:

[ 1763.897947] FAT: Filesystem error (dev sdd1)
[ 1763.897950] fat_get_cluster: invalid cluster chain (i_pos 0)
[ 1763.897954] File system has been set read-only
[ 1764.905287] FAT: Filesystem error (dev sdd1)
[ 1764.905290] fat_get_cluster: invalid cluster chain (i_pos 0)
[ 1766.495348] FAT: Filesystem error (dev sdd1)
[ 1766.495351] fat_get_cluster: invalid cluster chain (i_pos 0)

[pyrus]

I had the same problem with various types of USB memory sticks on Mint 13 Maya (MATE edition). I actually had two problems:
a) One of my sticks (that I had copied from the Mint ISO) was formatted as an ISO-9660 (CD) format filesystem
b) Other sticks were mounted read-write but my user only had read-only access to them

For the first problem I guess I'm stuck with the restriction of the filesystem, but for the others I created a UDEV rule to give myself read-write access as follows:

1. Create a file in /etc/udev/rules.d, e.g. 90-usb-disks.rules
2. Place the following in the new file:

Code: Select all

# UDEV Rules to change the permission of USB disks
#

KERNEL=="sd*[0-9]", ATTR{removable}=="1", ENV{ID_BUS}=="usb", MODE="0666"


In Mint I didn't even have to restart the UDEV service as creating the file triggers the new rules to be loaded

This is based on the advice on AskUbuntu here: http://askubuntu.com/questions/17540/ho ... able-drive with changed MODE value.