Can't format SD Disks on Apple Mac or delete data from SD Cards [duplicate]

Solution 1:

Well, your post was certainly entertaining enough. Thanks for that.

I know it's not the answer you are looking for. But, it does look like the SD card is stuck in read-only mode. You've done everything you can. It really isn't that difficult.

It acts like it would if there was a write-protect switch on the card. It sounds like you confirmed it did not, but maybe just double check, one more time? The thought that came to mind was maybe you are using a mini-SD card in a mini-sd to sd adapter. And maybe you looked on the adapter, but not the mini-sd card itself? I don't know, just throwing that out there. If there is an adapter, maybe the adapter itself went bad? I don't remember if you mentioned if you tried a different card reader. Maybe the reader went bad?

Other than that, it's a pretty common failure for something like this to "fail" in a read-only mode. So, my gut tells me the card went bad.

Looks like you are on the right track, just replacing it. Maybe you can get the bad one replaced under warranty being it is new. Let us know what you figure out.

Solution 2:

Such read-only issues happen to me all the time when I use iso-images.

What I do to fix such problems:

Note that <yoursdcard> is a device and not a partition, so for example sdc

Boot some kind of linux
Open a terminal
Find out what device your sd card is and verify it by using sudo fdisk /dev/<yoursdcard> -l or to get the device name too you could also use sudo parted /dev/<yoursdcard> -l

WARNING: The following command will destroy all data on /dev/<yoursdcard> so make sure that <yoursdcard> is the right device!!!!

Execute sudo dd if=/dev/zero of=/dev/<yoursdcard> bs=1000000 count=50
Execute sudo fdisk /dev/<yoursdcard>
Now use the command o to create a new MSDOS partition table on your sdcard, then use the n command to add a new partition and use w to write the changes to your sdcard and exit fdisk
Now use sudo mkfs -t <filesystem you want> /dev/<yoursdcard>1 to format your partition
Now your sdcard should work again

If that doesn't work:

Open terminal
Find out what device <yoursdcard> is
Execute sudo su
Execute echo "0" > /sys/block/<yoursdcard>/ro

Solution 3:

Keep in mind the card might simply be broken. They have some flash and a controller on board. If the card thinks it has issues it will go offline completely or go read-only if it has not enough working flash cells to write. Sometimes the controller keeps accounting information for the flash chip, which can get corrupted causing it to start in safe mode and not allow anything. To get past this type of stuff, you need a 'true' SD card reader, not a Mass Storage-only reader. The 'real' SD interfaces have access to the controller and might give you the information you need.

Solution 4:

Ah, yes. The Ubuntu image uses some sort of weird format that breaks most formatting utilities. I imagine it's some sort of thing they do so that the images work on DVDs. I know this well (read: I keep needing to make Ubuntu install disks, and I hate formatting them afterward), and it is very annoying.

Use Gparted on Ubuntu (the VM) to delete all partitions on the drive, then add a new FAT32 partition. Note: I am pretty sure that GParted uses the root password, not the normal one you use to log in. If you do not know your root password, it is likely that you have not set it. Run "sudo passwd" to set a root password, and then use that to open GParted. You can also use "sudo gparted".

Or, find and install the free program SDFormatter4 on Windows (Note: Works under WINE in Ubuntu, too) and use it to format the card in overwrite mode. This has a better chance of working, as much as I dislike proprietary software.

Both of these have better luck at formatting the cards than the built-in utilities.

Of course, SD cards and USB drives purposely fail into read-only mode to give you a chance at data recovery. If that card is remotely new, this should not happen, but it is possible. I also suggest Samsung or Sandisk cards, as Kingston cards are often fakes and rapidly fail. I actually had this very problem occur once, and it was actually a card failure. I hope that this is not the case for you.