I am trying to format a microSD card which was previously used in a Windows Phone. Currently the microSD card is in a Samsung Galaxy Ace Plus (GT-S7500) running Android 2.3.6. I have tried erasing the memory from the Settings menu and now I have plugged the USB and givin it a go from Ubuntu.

Every time I try to format (or manually delete) data, every file and directory seem to stay put.

I thought it could be a microSD card corruption problem, but as I type

sudo fsck -a /dev/sdc

The only warning message I get is:

0x41: Dirty bit is set. Fs was not properly unmounted and some data may be corrupt.
Automatically removing dirty bit.

Then I issue the command one more time and the check is fine.

Is there anything I can do to format this microSD card?

Update: Running gparted I get this error:

plain floppy: device "/dev/sdc" busy (Resource temporarily unavailable):
Cannot initialize '::'
mlabel: Cannot initialize drive
  • From the context (also the one given on the answer), it might be worth trying: sudo cfdisk /dev/sdc, delete the partition, re-create it, and then create the file system anew (which should be possible via the Android device by formatting it). This time it's a "clean partition" then, so nothing should be "locked".
    – Izzy
    Commented Dec 28, 2015 at 19:21

1 Answer 1


This is due to a bug in fsck.

 # fsck.vfat -v -a -w /dev/sda1

The above command automatically write changes to disk.

The dirty bit is set and cleared in the kernel, when mounting and unmounting a device;

or if its not working try this HDD Low Level Format Tool.This will help you format microSD completely.

  • Thank you for your answer. Unfortunately all files are still on the microSD card.
    – haunted85
    Commented Dec 28, 2015 at 17:55
  • Can u please recheck the SD Card whether it is locked or not? And i have updated the Answer.
    – PSN
    Commented Dec 28, 2015 at 17:58
  • Thank you for the update. It seems to be locked. I tried to write a new file on the microSD and on the next mount it was gone. Unfortunately I can't use Windows.
    – haunted85
    Commented Dec 28, 2015 at 18:11

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