USB Stick dead after syslinux A: on windows

[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]

use "additional options" and attach the file

[veteran]

Here is the dmesg output (attachement)

[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  )

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

Code Select Expand

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

Code Select Expand


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]

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

[veteran]

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]

and what device node can you see in dmesg?

[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]

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]

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

because of the missing device nodes

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