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How to Force Format USB drive? (Permissions lost)

Hi all,

Normally I would just buy a new one - but I am stuck at sea for 2 months! 😟

I have a 32GB San disk USB Cruze (USB Stick)
I have owned it from new and used it on the same computer. For some reason I have lost permissions for it. I can read, but that is all.
I wish to either regain ownership of the USB stick and therefore have full permissions or I don't mind formatting and starting from scratch.

A long time has been spent on this, with no light seen at the end of the tunnel..!

In DiskUtility as I have no persmissions I cannot do anything (First Aid or Restore) except view the USB stick
In Terminal I keep coming accross "Permission denied". The route of the USB is; /dev/disk0s2

Can I force a format or anything? I am not a computer wizard, so any terminal commands to help, please include what I need, I sometimes get lost when people say <something> <something> i'm not always sure what they are refering to..

I look forward to seeing if there is a solution, it would really save me with regards to my studies whilst i'm at sea. 😀

If there is a program (a small one) I maybe able to download it, if there's one to brute force a format..

Hope someone can help.. 😎

Thanks Matt

MacBook Pro (Retina, Mid 2012), iOS 6.0.1

Posted on Sep 10, 2013 5:35 AM

27 replies

Sep 10, 2013 9:51 AM in response to John_ J

Matts-MacBook-Pro-2:~ Matt$ diskutil repairDisk 32GB\ USB

A whole disk must be specified

Matts-MacBook-Pro-2:~ Matt$

😐

John_ J

Level 1

70 points

Sep 10, 2013 10:02 AM in response to wheretofindmatt

Oops, try this instead...

In Terminal (type):

"diskutil repairVolume 32GB\ USB"

Sep 10, 2013 10:11 AM in response to John_ J

I have a dirty USB.. 😁

Matts-MacBook-Pro-2:~ Matt$ diskutil repairVolume 32GB\ USB

Started file system repair on disk1s1 32GB USB

Checking file system

** /dev/disk1s1 (NO WRITE)

** Phase 1 - Preparing FAT

** Phase 2 - Checking Directories

** Phase 3 - Checking for Orphan Clusters

Free space in FSInfo block (1234069) not correct (1234086)

Fix? no

1577 files, 19745376 KiB free (1234086 clusters)

MARK FILE SYSTEM CLEAN? no

***** FILE SYSTEM IS LEFT MARKED AS DIRTY *****

Finished file system repair on disk1s1 32GB USB

Matts-MacBook-Pro-2:~ Matt$

John_ J

Level 1

70 points

Sep 10, 2013 10:34 AM in response to wheretofindmatt

I assume the volume repair did not fix the problem. Since we've tried to repair and that did not work, let's erase and repartion the whole volume.

In Terminal (type):

"diskutil eraseVolume HFS+ 32GB\ USB /Volumes/32GB\ USB"

Csound1

Level 9

59,973 points

Sep 10, 2013 10:49 AM in response to wheretofindmatt

Anyone on board with a camera that takes SD cards or a Winbox with an SD card slot.

If yes format the card in one of those 2 options. If they can't read/write to it you should assume that it is kaput.

Sep 11, 2013 12:32 AM in response to John_ J

Hi John,

That didn't work either.. 😝

Matts-MacBook-Pro-2:~ Matt$ diskutil eraseVolume HFS+ 32GB\ USB /Volumes/32GB\ USB

Started erase on disk1s1 32GB USB

Unmounting disk

Error: -69874: Couldn't modify partition map

Matts-MacBook-Pro-2:~ Matt$

Csound - it's a USB stick not an SD card..

dkbeyond

Level 1

0 points

Apr 17, 2014 4:55 PM in response to wheretofindmatt

Hey Matt, i was wondering if you were able to find a solution for the flashdrive? This is the same exact problem i am having right now and i cannot find the answer anywhere.

dkbeyond

Level 1

0 points

Jun 6, 2014 3:57 PM in response to wheretofindmatt

When i do it this message pops up. Any idea what i have to do or whats going wrong?

A volume was specified instead of a whole disk: BEYOND

Specify a whole disk, or instead use diskutil eraseVolume to erase a volume on a specific partition

Dereks-MacBook-Pro:~ dKBeyond$

dkbeyond

Level 1

0 points

Jun 6, 2014 4:01 PM in response to wheretofindmatt

I think i did it correctly now, but now this pops up.

Started erase on disk1s1 BEYOND

Unmounting disk

Error: -69874: Couldn't modify partition map

Dereks-MacBook-Pro:~ dKBeyond$

Jun 16, 2016 5:02 AM in response to John_ J

SO in my case, what command should I type? This is what I got:

drwxrwxrwx@ 1 FallenAngel staff 4096 Dec 31 1979 DISK_IMG

lrwxr-xr-x 1 root admin 1 Jun 16 17:34 Macintosh HD -> /

drwxrwxrwx 0 root wheel 0 Jun 16 19:43 MobileBackups

drwxrwxrwx@ 1 FallenAngel staff 4096 Jun 16 19:43 XXX

In this case, FallenAngel is me (and I am suddenly a "staff"), and the USB which I had inserted has 2 different drives. DISK_IMG and XXX. I can access and reformat XXX, but I simply could not reformat DISK_IMG.

please advise.

Eric Root

Level 10

684,057 points

Jun 16, 2016 7:21 AM in response to fallenangelsin

You might want to consider starting a new discussion. Since this one is a couple of years old, less people are likely to look at it. You can link to this one.

Sep 16, 2016 12:02 AM in response to wheretofindmatt

Hey guys. I fixed my drive. (Same 32GB flash). None of the usual solutions or terminal fixed it.

What I did was - 1.) installed Paragon NTFS.

2.) Restart

3.) Delete all of the files from the flash drive

4.) error, hit continue, let it stop flashing

5.) repair disk using utility

6.) reformat the flash drive

Boom! Works 🙂

How to Force Format USB drive? (Permissions lost)