SD card suddenly read-only

[Dotan Cohen]

2008/10/14 Willy K. Hamra <w.hamra1987 at gmail.com>:
> cherryfinals wrote:
>> --- On Mon, 10/13/08, Dotan Cohen <dotancohen at gmail.com> wrote:
>>
>>> From: Dotan Cohen <dotancohen at gmail.com>
>>> Subject: SD card suddenly read-only
>>> To: "kubuntu-users." <kubuntu-users at lists.ubuntu.com>
>>> Date: Monday, October 13, 2008, 7:27 PM
>>> I have been moving files back and forth between an PDA (Dell
>>> Axim) and
>>> my personal computer (the Kubuntu machine) via SD card all
>>> day.
>>> Suddenly, the Kubuntu machine insists that the card is
>>> read-only and
>>> will not write to it. Even reseting the machine and
>>> switching card
>>> readers does not help. The Axim still writes to the card
>>> just fine.
>>> What could be the cause?
>>>
>>> Thanks in advance.
>>>
>> Did you accidentally slip the little slide lock on the side of the
> card? I've done that a couple of times, when in a hurry.
>>
>> Stan
>
> don't think so, since Axim is still writing to it.
> check your mounts. type "mount" in konsole and see it's mount options,
> is there an "ro" option? if yes, umount it, and try to manually mount it
> with the "rw" option, the command should look like:
> sudo mount /dev/ur_sd_card /media/somewhere_here -o rw
> you can of course add the "-t file)system" option if you want.
> now see if you can writ to it.
>
> as to why this might happen? sometimes, if a filesystem is improperly
> unmounted, unplugged without safely removing first, and the filesystem
> is a non-linux filesystem like FAT or NTFS, the system gets scared that
> there might be corruption on the filesystem, and since such fs don't
> have a proper fsck program in linux, they get mounted as read-only to
> prevent further damage. if you type "dmesg | tail" after plugging your
> card, you should see some info about this read-only mount, and it's
> reasons. sometimes, like NTFS, you might need to use the force option in
> order to mount an improperly unmounted fs as rw, so the command will end
> with "-o rw,force".
> hope this helps you.

hardy2 at hardy2-laptop:~$ dmesg | tail
[ 1904.925562] sd 2:0:0:3: Attached scsi generic sg5 type 0
[ 1907.366009] FAT: Filesystem panic (dev sdb1)
[ 1907.366016]     fat_get_cluster: invalid cluster chain (i_pos 0)
[ 1907.366020]     File system has been set read-only
[ 1927.067153] FAT: Filesystem panic (dev sdb1)
[ 1927.067160]     fat_get_cluster: invalid cluster chain (i_pos 0)
[ 2090.004226] FAT: Filesystem panic (dev sdb1)
[ 2090.004233]     fat_get_cluster: invalid cluster chain (i_pos 0)
[ 2112.759870] FAT: Filesystem panic (dev sdb1)
[ 2112.759877]     fat_get_cluster: invalid cluster chain (i_pos 0)

The economy is bad, but that should make the SD card feel more
comfortable that I will not replace him. Why is it panicing then?

-- 
Dotan Cohen

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