D&C GLug - Home Page

[ Date Index ] [ Thread Index ] [ <= Previous by date / thread ] [ Next by date / thread => ]

Re: [LUG] how to fix read only USB key?

 


Sent from my iPhone

> On 6 Jun 2015, at 09:02, Eion MacDonald <eionmac@xxxxxxxxxxxxxx> wrote:
> 
> 
> 
>> On 05/06/2015 20:29, alex wrote:
>> not sure if this would work but it might be worth a try,i have never
>> used on a usb key
>> 
>> http://hddguru.com/software/HDD-LLF-Low-Level-Format-Tool/
>> 
>>> On 05/06/2015 20:27, alex wrote:
>>> not sure if this would work but it might be worth a try,i have never
>>> used on a usb key
>>> 
>>> http://hddguru.com/software/HDD-LLF-Low-Level-Format-Tool/
> 
> Tried, a number of low level format tools including HDDGURU. No joy,
> These report 'unable to access disc' 'locked file system'
> -- 

a) is there a physical switch on the device, like a small slider or dip switch - 
some devices like mmc:sdcards have these to force copy protection.

b) are trying to use these tools on the unmounted device ? ie plug in deivices show 
as (commands to manage a raw disk wont work if its mounted) 

/dev/sdXY   (XY beign specific to your use case) 

mounts to. for example. /media/myusb

Thus {all commands should be run as root}

run umount /dev/sdXY

cfdisk /dev/sdXY 
or fdisk /dev/sdXY

print the partition table take note of layout 
delete all partitions on the disk
go into expert mode , find the option to (re)create a dos partition table - do it - 
this ensures any coruption in the table is removed, 

write the changes to disk

wait a few mins then reboot - leave the disk inserted

as root again 

type df to check nothing magic happened and the usb should not be mounted. 

go back to cfdisk or fdisk /dev/sdXY

create 1 partition the full size of the disk

write it 

reboot (keep disk in machine) 

log in as root again 

format the disk as vfat = extended dos ... if < 1gb 

if > 1gb and only using on linux machines ext4 should work or brtfs 

if > 1gb and using on multiple machines format the partition via windows for a more 
consistent end result. 

i dont recall the exact command but its something like this 
mkfs.vfat /dev/sdXY

once formated you can then 

mount /dev/sdXY -t vfat /media/myusb

ps on windows there is this command 

format /mbr <driveletter>

which will do all of the above for you. 




> regards
> Eion MacDonald
> 
> -- 
> The Mailing List for the Devon & Cornwall LUG
> http://mailman.dclug.org.uk/listinfo/list
> FAQ: http://www.dcglug.org.uk/listfaq

-- 
The Mailing List for the Devon & Cornwall LUG
http://mailman.dclug.org.uk/listinfo/list
FAQ: http://www.dcglug.org.uk/listfaq