Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

My company was burning some microSD cards (4000 of them) and the multi burning machine we were using gives us the option to make the microSD read-only.

I didn't know this was possible, but apparently it flips a binary switch in the microSD card.

We now need to reformat all 4000 of the microSD cards and start fresh. We cannot format them because they are read only. I am not using a SD adapter so the possibility of the lock switch is a non issue.

Gparted cannot format them and running this command:

sudo mount -o remount,rw  /media/48EC-B32A

… returns this error:

cannot remount block device /dev/sdb1 read-write, is write-protected

Is there any way to force format these or are they permamantly gone?

share|improve this question
+1 good question. Unfortulatelly, I think the only way is using the hardware lock. – Diogo May 25 '12 at 17:12
Are you able to remove the partition completely and recreate it? It may be that the partition is RO but you should be able to remove it still, instead of reformating. – Nick R May 28 '12 at 14:18
See also… – derobert May 30 '12 at 19:33
Recall what brand your multi-burning machine was? – digitxp May 31 '12 at 21:50
Tell us more about this "burning" machine. – LawrenceC Jun 2 '12 at 13:59

The SD card should be unmounted before attempting format.

You will probably need to use mkdosfs

for FAT16

mkdosfs /dev/sdb2 -F16

or for FAT32

mkdosfs /dev/sdb2 -F32
share|improve this answer

I have found more information on this:

SD cards have a physical lock, to write protect the card. MicroSD cards don't have the lock, but the SD adapter has it, and it can lock-unlock the card.

So, try to put the card in an adapter and slid the lock a few times, leaving it on unlocked.

share|improve this answer

Sorry, for previous answer, I mixed up!

Can you use the something like HirenBoot CD?

Maybe that helps.

share|improve this answer
Original poster specifically mentions that mount -o remount,rw fails, you're suggesting essentially the same thing. – haimg Jun 3 '12 at 16:53

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .