USB Stick dead after syslinux A: on windows

Started by veteran, September 08, 2009, 10:03:08 AM

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veteran

Hi

I was following your manual here: http://www.plop.at/de/ploplinux.html#licreateusbstep

After Step 5: 
syslinux f:(on my system syslinux a:)

I tried to boot linux from usb, but there was an error. (grub stage 15  (or somewhat like this))

Then I wanted to try to install something other on the usb-stick but now it won't be recognized correctly by the system (neither windows, nor linux)

For Windows it seems to be not existing - tested on 2 PCs

In Linux the same (Debian 2.6.18-5-686), dmesg | grep usb reports no difference before and after putting the stick in to the computer
But it was working before I did syslinux a: (I made a backup of the data on it)

Do you have an idea on how to get this (8GB) USB stick back to work?   


Thank you for your help

Michael

Elmar

hi,
please post the complete dmesg with the stick connected

regards
elmar

veteran


Hi,
Thank you for your quick reply!

Posting the whole dmesg output of my computer is here unfortunately not possible...  ;)

The following error or errors occurred while posting this message:
The message exceeds the maximum allowed length (20000 characters).

Any suggestions?

Best regards,
Michael

Elmar


veteran


Elmar

on your stick is one partition availalbe as /dev/sdc1
are you able to mount /dev/sdc1?

veteran

Oh yes, I didn't see that (should go to bed earlier  :D )

No, unfortunately not:


# mount /dev/sdc1 /mnt/testusb -t vfat
mount: special device /dev/sdc1 does not exist

Elmar

i dont know how healthy your debian installation is. so only for testing, please burn a plop linux live cd, boot it and try to mount the stick. you have to check  the device node again with dmesg.

there can be some reasons why its not possible to mount it and why windows does not see it. we can try some things to rescue the stick data.
if you simply want a working stick, a fast way would be to clear the mbr, write a new mbr, partition the stick and format it.

its your choice

veteran


I don't need the data on the stick.
It should only work again.
So clearing the mbr, writing a new mbr an format it would be the best.

Elmar

ok, do you need help to do it?

if yes, whats the output of
ls -l /dev/sdc /dev/sdc1

veteran

Yes, please.

#ls -l /dev/sdc /dev/sdc1
ls: /dev/sdc: Datei oder Verzeichnis nicht gefunden
ls: /dev/sdc1: Datei oder Verzeichnis nicht gefunden

Elmar

ohh, you debian is not workiing well
make

mknod /dev/sdc b 8 32
mknod /dev/sdc1 b 8 33
chmod 660 /dev/sdc /dev/sdc1


then try to mount again /dev/sdc1
you know, you have to work as user root

veteran

Thanks. I did that - but... :


# mknod /dev/sdc b 8 32
# mknod /dev/sdc1 b 8 33
# chmod 660 /dev/sdc /dev/sdc1
# mount /dev/sdc1 /mnt/testusb/ -t vfat
mount: /dev/sdc1 is not a valid block device

Elmar

#13

unplug and plug in the usb stick. do you get a new device node?

veteran

#14
I'm not sure about that, but now the output of # ls -l /dev/sdc /dev/sdc1 changed:

# ls -l /dev/sdc /dev/sdc1
brw-rw---- 1 root root 8, 32 2009-09-08 11:26 /dev/sdc
brw-rw---- 1 root root 8, 33 2009-09-08 11:26 /dev/sdc1


Elmar


veteran

Hmm as it seems the USB Stick is not present anymore

(After rebooting I did this again)

# mknod /dev/sdc b 8 32
# mknod /dev/sdc1 b 8 33
# chmod 660 /dev/sdc /dev/sdc1
# mount /dev/sdc1 /mnt/testusb/ -t vfat
mount: /dev/sdc1 is not a valid block device

Here the new dmesg output (attachement)

Elmar

the usb stick was connected when you created the dmesg output?
whats the status after a replug?

veteran

#18
Yes, it was connected.
Now I unplugged it, did a dmesg, then
replugged it, did a dmesg, but there was no difference in the files

Why did you mean that my debian install isn't healthy?

So, now I checked it with another system which should be healthy... and yes, the stick gets mounted correctly as it seems.
I can see the files which I moved to the usb-stick.

Elmar

Quote from: veteran on September 09, 2009, 12:04:14 PM
Why did you mean that my debian install isn't healthy?

because of the missing device nodes

Quote from: veteran on September 09, 2009, 12:04:14 PM
So, now I checked it with another system which should be healthy... and yes, the stick gets mounted correctly as it seems.
I can see the files which I moved to the usb-stick.

maybe its a hardware failure on the pc? the stick seems to be okay when its possible to detect/mount on another pc