formatting protected USB memory sticks

[Karl Larsen]

Colin Rowat wrote:
> Thank you Karl - your instructions were exactly what I needed: clear,
> and basic.  I'm still running into problems with - I think - the write
> protection, though.  I'll indicate, below, where I seem to go wrong:
>
>   
>> 1. Find the name of your memory:
>>     
>
> No problem: /dev/scd1 (/media/Autorun) and /dev/sdb1 (/media/DISK_IMG). 
> The former contains the preloaded material that I wish to wipe out; it
> shows as 100% full.
>
>   
>> 2. Un-mount the hard drive or USB memory:
>>     
>
> No problem.
>  
>   
>> 3. Run fdisk to remove, make partitions:
>>
>>         For example I will say my memory is /dev/sdf and I want to use 
>> fdisk to change things. To use fdisk in a terminal type sudo fdisk 
>> /dev/sdf and give your password. You get this:
>>
>> karl at karl-desktop:~$ sudo fdisk /dev/sdf
>> [sudo] password for karl:
>>
>> Command (m for help):
>>     
>
> I received:
>
> You will not be able to write the partition table.
> Note: sector size is 2048 (not 512)
> Device contains neither a valid DOS partition table, nor Sun, SGI or OSF
> disklabel
>
> before I got the "Command (m for help)" message.
>  
>   
>> Command (m for help): p
>>
>> Disk /dev/sdf: 4043 MB, 4043308544 bytes
>> 255 heads, 63 sectors/track, 491 cylinders
>> Units = cylinders of 16065 * 512 = 8225280 bytes
>> Disk identifier: 0x91f72d24
>>
>>    Device Boot      Start         End      Blocks   Id  System
>> /dev/sdf1   *           1         123      987966    e  W95 FAT16 (LBA)
>> /dev/sdf2             124         491     2955960   83  Linux
>>     
>
> The first block looks the same for me (but 15 cylinders, not 491), but
> the Device Boot table is empty.
>  
>   
>> Command (m for help): d
>>     
>
> I am told "no partition is defined yet".
>
>   
>> Command (m for help): n
>> Command action
>>    e   extended
>>    p   primary partition (1-4)
>> p
>> Partition number (1-4): 1
>> First cylinder (1-491, default 1):
>> Using default value 1
>> Last cylinder or +size or +sizeM or +sizeK (1-491, default 491):
>> Using default value 491
>>     
>
> No problem.
>  
>   
>> If I wanted to save this I would use w to exit. But I want to save the 
>> current things so I quit with q.
>>     
>
> Here, I enter "w" and am told "unable to write /dev/scd1".  As a result,
> I do not continue.
>  
> Is it the case that I am not overcoming the write protection?  The USB
> stick has been branded by the organisation that gave it to me, so I
> don't know the manufacturer - and, thus, cannot ask them how to reformat
> it.
>
> Again, if you could provide any further suggestions, I would be very
> grateful for it.
>
> Thank you,
>
> Colin Rowat
>
>
>
>   
    Do NOT use sudo fdisk /dev/scd1! This is wrong. Use sudo fdisk /dev/scd.

Karl

I will add this to the paper I sent you.



-- 

	Karl F. Larsen, AKA K5DI
	Linux User
	#450462   http://counter.li.org.
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